图表 (lv_chart)¶
部件和样式¶
LV_PART_MAIN图表的背景。使用所有典型的背景和线条（用于分割线）相关的样式属性。填充使系列区域变小。对于柱状图，pad_column设置相邻索引列之间的间距。LV_PART_SCROLLBAR如果图表被缩放，则使用的滚动条。有关详细信息，请参阅 基础对象 的文档。LV_PART_ITEMS指代折线或柱状系列。折线图：线条属性用于线条。
width、height、bg_color和radius用于设置点的外观。柱状图：典型的背景属性用于样式化柱状图。
pad_column设置同一索引列之间的间距。
LV_PART_INDICATOR指代折线图和散点图上的点（小圆圈或方块）。LV_PART_CURSOR线条属性用于样式化光标。width、height、bg_color和radius用于设置点的外观。LV_PART_TICKS线条和文本样式属性用于样式化刻度。
用法¶
图表类型¶
以下是数据展示类型：
LV_CHART_TYPE_NONE不显示任何数据。可用于隐藏系列。LV_CHART_TYPE_LINE在数据点之间绘制线条，并/或在数据点上绘制点（矩形或圆形）。LV_CHART_TYPE_BAR绘制柱状图。LV_CHART_TYPE_SCATTER绘制 X/Y 图表，显示点和点之间的线条。
可以使用 lv_chart_set_type(chart, LV_CHART_TYPE_...) 指定展示类型。
数据系列¶
可以通过 lv_chart_add_series(chart, color, axis) 向图表添加任意数量的系列。这会分配一个 lv_chart_series_t 结构，其中包含所选的 color 和一个用于数据点的数组。
axis 可以具有以下值：
LV_CHART_AXIS_PRIMARY_Y左轴LV_CHART_AXIS_SECONDARY_Y右轴LV_CHART_AXIS_PRIMARY_X底部轴LV_CHART_AXIS_SECONDARY_X顶部轴
axis 指定应使用哪个轴的范围来缩放值。
lv_chart_set_ext_y_array(chart, ser, value_array) 使图表对给定系列使用外部数组。
value_array 应如下所示：lv_coord_t * value_array[num_points]。数组大小需要足够大以容纳该系列的所有点。
数组的指针将保存在图表中，因此它需要是全局、静态或动态分配的。
注意：在更新外部数据源后，应调用 lv_chart_refresh(chart) 来更新图表。
可以使用 lv_chart_get_y_array(chart, ser) 获取系列的值数组，该数组可与 ext_array 或普通数组一起使用。
对于 LV_CHART_TYPE_SCATTER 类型，也可以使用 lv_chart_set_ext_x_array(chart, ser, value_array) 和 lv_chart_get_x_array(chart, ser)。
修改数据¶
有多种方法可以设置系列的数据：
在数组中手动设置值，例如
ser1->points[3] = 7，然后使用lv_chart_refresh(chart)刷新图表。使用
lv_chart_set_value_by_id(chart, ser, id, value)，其中id是要更新的点的索引。使用
lv_chart_set_next_value(chart, ser, value)。使用
lv_chart_set_all_value(chart, ser, value)将所有点初始化为给定值。
使用 LV_CHART_POINT_NONE 作为值可以使库跳过绘制该点、列或线段。
对于 LV_CHART_TYPE_SCATTER 类型，也可以使用 lv_chart_set_value_by_id2(chart, ser, id, value) 和 lv_chart_set_next_value2(chart, ser, x_value, y_value)。
更新模式¶
lv_chart_set_next_value 的行为取决于更新模式：
LV_CHART_UPDATE_MODE_SHIFT将旧数据向左移动，并将新数据添加到右侧。LV_CHART_UPDATE_MODE_CIRCULAR以循环方式添加新数据，例如心电图。
可以使用 lv_chart_set_update_mode(chart, LV_CHART_UPDATE_MODE_...) 更改更新模式。
点的数量¶
可以通过 lv_chart_set_point_count(chart, point_num) 修改系列中的点数。默认值为 10。
注意：这也会影响为系列分配外部缓冲区时处理的点数，因此需要确保外部数组足够大。
处理大量点¶
在折线图中，如果点的数量大于水平像素数，图表将仅绘制垂直线，以提高大量数据的绘制效率。 例如，如果每像素有 10 个点，LVGL 会搜索最小值和最大值，并在它们之间绘制垂直线，以确保不会遗漏峰值。
垂直范围¶
可以使用 lv_chart_set_range(chart, axis, min, max) 指定 y 方向的最小值和最大值。
axis 可以是 LV_CHART_AXIS_PRIMARY（左轴）或 LV_CHART_AXIS_SECONDARY（右轴）。
点的值将按比例缩放。默认范围为：0..100。
分割线¶
可以通过 lv_chart_set_div_line_count(chart, hdiv_num, vdiv_num) 修改水平和垂直分割线的数量。
默认设置为 3 条水平分割线和 5 条垂直分割线。
如果某一侧有可见边框且没有填充，则分割线会绘制在边框上，因此不会显示。
为系列设置默认起点¶
如果希望绘图从系列的默认起点 point[0] 以外的点开始，可以使用 lv_chart_set_x_start_point(chart, ser, id) 设置新的起点索引。
注意：LV_CHART_UPDATE_MODE_SHIFT 也会更改 start_point。
刻度线和标签¶
可以使用 lv_chart_set_axis_tick(chart, axis, major_len, minor_len, major_cnt, minor_cnt, label_en, draw_size) 为轴添加刻度线和标签。
axis可以是LV_CHART_AXIS_X/PRIMARY_Y/SECONDARY_Ymajor_len是主刻度线的长度minor_len是次刻度线的长度major_cnt是轴上的主刻度线数量minor_cnt是两个主刻度线之间的次刻度线数量label_en为true时启用主刻度线上的标签绘制draw_size绘制刻度线和标签所需的额外大小（从 20 像素开始，如果刻度线/标签被裁剪则增加）
缩放¶
可以使用 lv_chart_set_zoom_x(chart, factor) 和 lv_chart_set_zoom_y(chart, factor) 分别在 x 和 y 方向上缩放图表。
如果 factor 为 256，则没有缩放。512 表示双倍缩放，依此类推。不允许小于 256 的值。
光标¶
可以使用 lv_chart_cursor_t * c1 = lv_chart_add_cursor(chart, color, dir); 添加光标。
dir 的可能值为 LV_DIR_NONE/RIGHT/UP/LEFT/DOWN/HOR/VER/ALL 或它们的 OR 值，用于指定光标应绘制的方向。
lv_chart_set_cursor_pos(chart, cursor, &point) 设置光标的位置。
pos 是一个指向 lv_point_t 变量的指针。例如：lv_point_t point = {10, 20};。如果图表被滚动，光标将保持在同一位置。
lv_chart_get_point_pos_by_id(chart, series, id, &point_out) 获取给定点的坐标。这对于将光标放置在给定点非常有用。
lv_chart_set_cursor_point(chart, cursor, series, point_id) 将光标固定在某个点上。如果点的位置发生变化（新值或滚动），光标将随点移动。
事件¶
LV_EVENT_VALUE_CHANGED当点击新点时发送。lv_chart_get_pressed_point(chart)返回被点击点的从零开始的索引。LV_EVENT_DRAW_PART_BEGIN和LV_EVENT_DRAW_PART_END会针对以下类型发送：LV_CHART_DRAW_PART_DIV_LINE_INIT在绘制分割线之前/之后使用，用于为任何额外绘图添加遮罩。以下字段已设置：part:LV_PART_MAINline_dsc
LV_CHART_DRAW_PART_DIV_LINE_HOR,LV_CHART_DRAW_PART_DIV_LINE_VER用于每条水平和垂直分割线。part:LV_PART_MAINid: 线的索引p1,p2: 线的点line_dsc
LV_CHART_DRAW_PART_LINE_AND_POINT用于折线图和散点图的线条和点。part:LV_PART_ITEMSid: 点的索引value: 第id个点的值p1,p2: 线的点draw_area: 点的区域line_dscrect_dscsub_part_ptr: 指向系列的指针
LV_CHART_DRAW_PART_BAR用于柱状图的矩形。part:LV_PART_ITEMSid: 点的索引value: 第id个点的值draw_area: 点的区域rect_dscsub_part_ptr: 指向系列的指针
LV_CHART_DRAW_PART_CURSOR用于光标线条和点。part:LV_PART_CURSORp1,p2: 线的点line_dscrect_dscdraw_area: 点的区域
LV_CHART_DRAW_PART_TICK_LABEL用于刻度线和标签。part:LV_PART_TICKSid: 轴value: 刻度线的值text:value转换为十进制或次刻度线上的NULLline_dsclabel_dsc
也可以查看 基础对象 的事件。
了解更多关于事件的信息。
示例¶
折线图¶
C code
GitHub#include "../../lv_examples.h"
#if LV_USE_CHART && LV_BUILD_EXAMPLES
void lv_example_chart_1(void)
{
/*Create a chart*/
lv_obj_t * chart;
chart = lv_chart_create(lv_scr_act());
lv_obj_set_size(chart, 200, 150);
lv_obj_center(chart);
lv_chart_set_type(chart, LV_CHART_TYPE_LINE); /*Show lines and points too*/
/*Add two data series*/
lv_chart_series_t * ser1 = lv_chart_add_series(chart, lv_palette_main(LV_PALETTE_RED), LV_CHART_AXIS_PRIMARY_Y);
lv_chart_series_t * ser2 = lv_chart_add_series(chart, lv_palette_main(LV_PALETTE_GREEN), LV_CHART_AXIS_SECONDARY_Y);
/*Set the next points on 'ser1'*/
lv_chart_set_next_value(chart, ser1, 10);
lv_chart_set_next_value(chart, ser1, 10);
lv_chart_set_next_value(chart, ser1, 10);
lv_chart_set_next_value(chart, ser1, 10);
lv_chart_set_next_value(chart, ser1, 10);
lv_chart_set_next_value(chart, ser1, 10);
lv_chart_set_next_value(chart, ser1, 10);
lv_chart_set_next_value(chart, ser1, 30);
lv_chart_set_next_value(chart, ser1, 70);
lv_chart_set_next_value(chart, ser1, 90);
/*Directly set points on 'ser2'*/
ser2->y_points[0] = 90;
ser2->y_points[1] = 70;
ser2->y_points[2] = 65;
ser2->y_points[3] = 65;
ser2->y_points[4] = 65;
ser2->y_points[5] = 65;
ser2->y_points[6] = 65;
ser2->y_points[7] = 65;
ser2->y_points[8] = 65;
ser2->y_points[9] = 65;
lv_chart_refresh(chart); /*Required after direct set*/
}
#endif
# Create a chart
chart = lv.chart(lv.scr_act())
chart.set_size(200, 150)
chart.center()
chart.set_type(lv.chart.TYPE.LINE) # Show lines and points too
# Add two data series
ser1 = chart.add_series(lv.palette_main(lv.PALETTE.RED), lv.chart.AXIS.PRIMARY_Y)
ser2 = chart.add_series(lv.palette_main(lv.PALETTE.GREEN), lv.chart.AXIS.SECONDARY_Y)
print(ser2)
# Set next points on ser1
chart.set_next_value(ser1,10)
chart.set_next_value(ser1,10)
chart.set_next_value(ser1,10)
chart.set_next_value(ser1,10)
chart.set_next_value(ser1,10)
chart.set_next_value(ser1,10)
chart.set_next_value(ser1,10)
chart.set_next_value(ser1,30)
chart.set_next_value(ser1,70)
chart.set_next_value(ser1,90)
# Directly set points on 'ser2'
ser2.y_points = [90, 70, 65, 65, 65, 65, 65, 65, 65, 65]
chart.refresh() # Required after direct set
带有自定义分割线的渐变区域折线图¶
C code
GitHub#include "../../lv_examples.h"
#if LV_USE_CHART && LV_DRAW_COMPLEX && LV_BUILD_EXAMPLES
static lv_obj_t * chart1;
static lv_chart_series_t * ser1;
static lv_chart_series_t * ser2;
static void draw_event_cb(lv_event_t * e)
{
lv_obj_t * obj = lv_event_get_target(e);
/*Add the faded area before the lines are drawn*/
lv_obj_draw_part_dsc_t * dsc = lv_event_get_draw_part_dsc(e);
if(dsc->part == LV_PART_ITEMS) {
if(!dsc->p1 || !dsc->p2) return;
/*Add a line mask that keeps the area below the line*/
lv_draw_mask_line_param_t line_mask_param;
lv_draw_mask_line_points_init(&line_mask_param, dsc->p1->x, dsc->p1->y, dsc->p2->x, dsc->p2->y,
LV_DRAW_MASK_LINE_SIDE_BOTTOM);
int16_t line_mask_id = lv_draw_mask_add(&line_mask_param, NULL);
/*Add a fade effect: transparent bottom covering top*/
lv_coord_t h = lv_obj_get_height(obj);
lv_draw_mask_fade_param_t fade_mask_param;
lv_draw_mask_fade_init(&fade_mask_param, &obj->coords, LV_OPA_COVER, obj->coords.y1 + h / 8, LV_OPA_TRANSP,
obj->coords.y2);
int16_t fade_mask_id = lv_draw_mask_add(&fade_mask_param, NULL);
/*Draw a rectangle that will be affected by the mask*/
lv_draw_rect_dsc_t draw_rect_dsc;
lv_draw_rect_dsc_init(&draw_rect_dsc);
draw_rect_dsc.bg_opa = LV_OPA_20;
draw_rect_dsc.bg_color = dsc->line_dsc->color;
lv_area_t a;
a.x1 = dsc->p1->x;
a.x2 = dsc->p2->x - 1;
a.y1 = LV_MIN(dsc->p1->y, dsc->p2->y);
a.y2 = obj->coords.y2;
lv_draw_rect(dsc->draw_ctx, &draw_rect_dsc, &a);
/*Remove the masks*/
lv_draw_mask_free_param(&line_mask_param);
lv_draw_mask_free_param(&fade_mask_param);
lv_draw_mask_remove_id(line_mask_id);
lv_draw_mask_remove_id(fade_mask_id);
}
/*Hook the division lines too*/
else if(dsc->part == LV_PART_MAIN) {
if(dsc->line_dsc == NULL || dsc->p1 == NULL || dsc->p2 == NULL) return;
/*Vertical line*/
if(dsc->p1->x == dsc->p2->x) {
dsc->line_dsc->color = lv_palette_lighten(LV_PALETTE_GREY, 1);
if(dsc->id == 3) {
dsc->line_dsc->width = 2;
dsc->line_dsc->dash_gap = 0;
dsc->line_dsc->dash_width = 0;
}
else {
dsc->line_dsc->width = 1;
dsc->line_dsc->dash_gap = 6;
dsc->line_dsc->dash_width = 6;
}
}
/*Horizontal line*/
else {
if(dsc->id == 2) {
dsc->line_dsc->width = 2;
dsc->line_dsc->dash_gap = 0;
dsc->line_dsc->dash_width = 0;
}
else {
dsc->line_dsc->width = 2;
dsc->line_dsc->dash_gap = 6;
dsc->line_dsc->dash_width = 6;
}
if(dsc->id == 1 || dsc->id == 3) {
dsc->line_dsc->color = lv_palette_main(LV_PALETTE_GREEN);
}
else {
dsc->line_dsc->color = lv_palette_lighten(LV_PALETTE_GREY, 1);
}
}
}
}
static void add_data(lv_timer_t * timer)
{
LV_UNUSED(timer);
static uint32_t cnt = 0;
lv_chart_set_next_value(chart1, ser1, lv_rand(20, 90));
if(cnt % 4 == 0) lv_chart_set_next_value(chart1, ser2, lv_rand(40, 60));
cnt++;
}
/**
* Add a faded area effect to the line chart and make some division lines ticker
*/
void lv_example_chart_2(void)
{
/*Create a chart1*/
chart1 = lv_chart_create(lv_scr_act());
lv_obj_set_size(chart1, 200, 150);
lv_obj_center(chart1);
lv_chart_set_type(chart1, LV_CHART_TYPE_LINE); /*Show lines and points too*/
lv_chart_set_div_line_count(chart1, 5, 7);
lv_obj_add_event_cb(chart1, draw_event_cb, LV_EVENT_DRAW_PART_BEGIN, NULL);
lv_chart_set_update_mode(chart1, LV_CHART_UPDATE_MODE_CIRCULAR);
/*Add two data series*/
ser1 = lv_chart_add_series(chart1, lv_palette_main(LV_PALETTE_RED), LV_CHART_AXIS_PRIMARY_Y);
ser2 = lv_chart_add_series(chart1, lv_palette_main(LV_PALETTE_BLUE), LV_CHART_AXIS_SECONDARY_Y);
uint32_t i;
for(i = 0; i < 10; i++) {
lv_chart_set_next_value(chart1, ser1, lv_rand(20, 90));
lv_chart_set_next_value(chart1, ser2, lv_rand(30, 70));
}
lv_timer_create(add_data, 200, NULL);
}
#endif
def draw_event_cb(e):
obj = e.get_target()
# Add the faded area before the lines are drawn
dsc = lv.obj_draw_part_dsc_t.__cast__(e.get_param())
if dsc.part != lv.PART.ITEMS:
return
if not dsc.p1 or not dsc.p2:
return
# Add a line mask that keeps the area below the line
line_mask_param = lv.draw_mask_line_param_t()
line_mask_param.points_init(dsc.p1.x, dsc.p1.y, dsc.p2.x, dsc.p2.y, lv.DRAW_MASK_LINE_SIDE.BOTTOM)
# line_mask_id = line_mask_param.draw_mask_add(None)
line_mask_id = lv.draw_mask_add(line_mask_param, None)
# Add a fade effect: transparent bottom covering top
h = obj.get_height()
fade_mask_param = lv.draw_mask_fade_param_t()
coords = lv.area_t()
obj.get_coords(coords)
fade_mask_param.init(coords, lv.OPA.COVER, coords.y1 + h // 8, lv.OPA.TRANSP,coords.y2)
fade_mask_id = lv.draw_mask_add(fade_mask_param,None)
# Draw a rectangle that will be affected by the mask
draw_rect_dsc = lv.draw_rect_dsc_t()
draw_rect_dsc.init()
draw_rect_dsc.bg_opa = lv.OPA._20
draw_rect_dsc.bg_color = dsc.line_dsc.color
a = lv.area_t()
a.x1 = dsc.p1.x
a.x2 = dsc.p2.x - 1
a.y1 = min(dsc.p1.y, dsc.p2.y)
coords = lv.area_t()
obj.get_coords(coords)
a.y2 = coords.y2
dsc.draw_ctx.rect(draw_rect_dsc, a)
# Remove the masks
lv.draw_mask_remove_id(line_mask_id)
lv.draw_mask_remove_id(fade_mask_id)
def add_data(timer):
# LV_UNUSED(timer);
cnt = 0
chart1.set_next_value(ser1, lv.rand(20, 90))
if cnt % 4 == 0:
chart1.set_next_value(ser2, lv.rand(40, 60))
cnt +=1
#
# Add a faded area effect to the line chart
#
# Create a chart1
chart1 = lv.chart(lv.scr_act())
chart1.set_size(200, 150)
chart1.center()
chart1.set_type(lv.chart.TYPE.LINE) # Show lines and points too
chart1.add_event_cb(draw_event_cb, lv.EVENT.DRAW_PART_BEGIN, None)
chart1.set_update_mode(lv.chart.UPDATE_MODE.CIRCULAR)
# Add two data series
ser1 = chart1.add_series(lv.palette_main(lv.PALETTE.RED), lv.chart.AXIS.PRIMARY_Y)
ser2 = chart1.add_series(lv.palette_main(lv.PALETTE.BLUE), lv.chart.AXIS.SECONDARY_Y)
for i in range(10):
chart1.set_next_value(ser1, lv.rand(20, 90))
chart1.set_next_value(ser2, lv.rand(30, 70))
timer = lv.timer_create(add_data, 200, None)
带滚动的轴刻度和标签¶
C code
GitHub#include "../../lv_examples.h"
#if LV_USE_CHART && LV_BUILD_EXAMPLES
static void draw_event_cb(lv_event_t * e)
{
lv_obj_draw_part_dsc_t * dsc = lv_event_get_draw_part_dsc(e);
if(!lv_obj_draw_part_check_type(dsc, &lv_chart_class, LV_CHART_DRAW_PART_TICK_LABEL)) return;
if(dsc->id == LV_CHART_AXIS_PRIMARY_X && dsc->text) {
const char * month[] = {"Jan", "Febr", "March", "Apr", "May", "Jun", "July", "Aug", "Sept", "Oct", "Nov", "Dec"};
lv_snprintf(dsc->text, dsc->text_length, "%s", month[dsc->value]);
}
}
/**
* Add ticks and labels to the axis and demonstrate scrolling
*/
void lv_example_chart_3(void)
{
/*Create a chart*/
lv_obj_t * chart;
chart = lv_chart_create(lv_scr_act());
lv_obj_set_size(chart, 200, 150);
lv_obj_center(chart);
lv_chart_set_type(chart, LV_CHART_TYPE_BAR);
lv_chart_set_range(chart, LV_CHART_AXIS_PRIMARY_Y, 0, 100);
lv_chart_set_range(chart, LV_CHART_AXIS_SECONDARY_Y, 0, 400);
lv_chart_set_point_count(chart, 12);
lv_obj_add_event_cb(chart, draw_event_cb, LV_EVENT_DRAW_PART_BEGIN, NULL);
/*Add ticks and label to every axis*/
lv_chart_set_axis_tick(chart, LV_CHART_AXIS_PRIMARY_X, 10, 5, 12, 3, true, 40);
lv_chart_set_axis_tick(chart, LV_CHART_AXIS_PRIMARY_Y, 10, 5, 6, 2, true, 50);
lv_chart_set_axis_tick(chart, LV_CHART_AXIS_SECONDARY_Y, 10, 5, 3, 4, true, 50);
/*Zoom in a little in X*/
lv_chart_set_zoom_x(chart, 800);
/*Add two data series*/
lv_chart_series_t * ser1 = lv_chart_add_series(chart, lv_palette_lighten(LV_PALETTE_GREEN, 2), LV_CHART_AXIS_PRIMARY_Y);
lv_chart_series_t * ser2 = lv_chart_add_series(chart, lv_palette_darken(LV_PALETTE_GREEN, 2),
LV_CHART_AXIS_SECONDARY_Y);
/*Set the next points on 'ser1'*/
lv_chart_set_next_value(chart, ser1, 31);
lv_chart_set_next_value(chart, ser1, 66);
lv_chart_set_next_value(chart, ser1, 10);
lv_chart_set_next_value(chart, ser1, 89);
lv_chart_set_next_value(chart, ser1, 63);
lv_chart_set_next_value(chart, ser1, 56);
lv_chart_set_next_value(chart, ser1, 32);
lv_chart_set_next_value(chart, ser1, 35);
lv_chart_set_next_value(chart, ser1, 57);
lv_chart_set_next_value(chart, ser1, 85);
lv_chart_set_next_value(chart, ser1, 22);
lv_chart_set_next_value(chart, ser1, 58);
lv_coord_t * ser2_array = lv_chart_get_y_array(chart, ser2);
/*Directly set points on 'ser2'*/
ser2_array[0] = 92;
ser2_array[1] = 71;
ser2_array[2] = 61;
ser2_array[3] = 15;
ser2_array[4] = 21;
ser2_array[5] = 35;
ser2_array[6] = 35;
ser2_array[7] = 58;
ser2_array[8] = 31;
ser2_array[9] = 53;
ser2_array[10] = 33;
ser2_array[11] = 73;
lv_chart_refresh(chart); /*Required after direct set*/
}
#endif
def draw_event_cb(e):
dsc = lv.obj_draw_part_dsc_t.__cast__(e.get_param())
if dsc.part == lv.PART.TICKS and dsc.id == lv.chart.AXIS.PRIMARY_X:
month = ["Jan", "Febr", "March", "Apr", "May", "Jun", "July", "Aug", "Sept", "Oct", "Nov", "Dec"]
# dsc.text is defined char text[16], I must therefore convert the Python string to a byte_array
dsc.text = bytes(month[dsc.value],"ascii")
#
# Add ticks and labels to the axis and demonstrate scrolling
#
# Create a chart
chart = lv.chart(lv.scr_act())
chart.set_size(200, 150)
chart.center()
chart.set_type(lv.chart.TYPE.BAR)
chart.set_range(lv.chart.AXIS.PRIMARY_Y, 0, 100)
chart.set_range(lv.chart.AXIS.SECONDARY_Y, 0, 400)
chart.set_point_count(12)
chart.add_event_cb(draw_event_cb, lv.EVENT.DRAW_PART_BEGIN, None)
# Add ticks and label to every axis
chart.set_axis_tick(lv.chart.AXIS.PRIMARY_X, 10, 5, 12, 3, True, 40)
chart.set_axis_tick(lv.chart.AXIS.PRIMARY_Y, 10, 5, 6, 2, True, 50)
chart.set_axis_tick(lv.chart.AXIS.SECONDARY_Y, 10, 5, 3, 4,True, 50)
# Zoom in a little in X
chart.set_zoom_x(800)
# Add two data series
ser1 = lv.chart.add_series(chart, lv.palette_lighten(lv.PALETTE.GREEN, 2), lv.chart.AXIS.PRIMARY_Y)
ser2 = lv.chart.add_series(chart, lv.palette_darken(lv.PALETTE.GREEN, 2), lv.chart.AXIS.SECONDARY_Y)
# Set the next points on 'ser1'
chart.set_next_value(ser1, 31)
chart.set_next_value(ser1, 66)
chart.set_next_value(ser1, 10)
chart.set_next_value(ser1, 89)
chart.set_next_value(ser1, 63)
chart.set_next_value(ser1, 56)
chart.set_next_value(ser1, 32)
chart.set_next_value(ser1, 35)
chart.set_next_value(ser1, 57)
chart.set_next_value(ser1, 85)
chart.set_next_value(ser1, 22)
chart.set_next_value(ser1, 58)
# Directly set points on 'ser2'
ser2.y_points = [92,71,61,15,21,35,35,58,31,53,33,73]
chart.refresh() # Required after direct set
显示按下点的值¶
C code
GitHub#include "../../lv_examples.h"
#if LV_USE_CHART && LV_BUILD_EXAMPLES
static void event_cb(lv_event_t * e)
{
lv_event_code_t code = lv_event_get_code(e);
lv_obj_t * chart = lv_event_get_target(e);
if(code == LV_EVENT_VALUE_CHANGED) {
lv_obj_invalidate(chart);
}
if(code == LV_EVENT_REFR_EXT_DRAW_SIZE) {
lv_coord_t * s = lv_event_get_param(e);
*s = LV_MAX(*s, 20);
}
else if(code == LV_EVENT_DRAW_POST_END) {
int32_t id = lv_chart_get_pressed_point(chart);
if(id == LV_CHART_POINT_NONE) return;
LV_LOG_USER("Selected point %d", (int)id);
lv_chart_series_t * ser = lv_chart_get_series_next(chart, NULL);
while(ser) {
lv_point_t p;
lv_chart_get_point_pos_by_id(chart, ser, id, &p);
lv_coord_t * y_array = lv_chart_get_y_array(chart, ser);
lv_coord_t value = y_array[id];
char buf[16];
lv_snprintf(buf, sizeof(buf), LV_SYMBOL_DUMMY"$%d", value);
lv_draw_rect_dsc_t draw_rect_dsc;
lv_draw_rect_dsc_init(&draw_rect_dsc);
draw_rect_dsc.bg_color = lv_color_black();
draw_rect_dsc.bg_opa = LV_OPA_50;
draw_rect_dsc.radius = 3;
draw_rect_dsc.bg_img_src = buf;
draw_rect_dsc.bg_img_recolor = lv_color_white();
lv_area_t a;
a.x1 = chart->coords.x1 + p.x - 20;
a.x2 = chart->coords.x1 + p.x + 20;
a.y1 = chart->coords.y1 + p.y - 30;
a.y2 = chart->coords.y1 + p.y - 10;
lv_draw_ctx_t * draw_ctx = lv_event_get_draw_ctx(e);
lv_draw_rect(draw_ctx, &draw_rect_dsc, &a);
ser = lv_chart_get_series_next(chart, ser);
}
}
else if(code == LV_EVENT_RELEASED) {
lv_obj_invalidate(chart);
}
}
/**
* Show the value of the pressed points
*/
void lv_example_chart_4(void)
{
/*Create a chart*/
lv_obj_t * chart;
chart = lv_chart_create(lv_scr_act());
lv_obj_set_size(chart, 200, 150);
lv_obj_center(chart);
lv_obj_add_event_cb(chart, event_cb, LV_EVENT_ALL, NULL);
lv_obj_refresh_ext_draw_size(chart);
/*Zoom in a little in X*/
lv_chart_set_zoom_x(chart, 800);
/*Add two data series*/
lv_chart_series_t * ser1 = lv_chart_add_series(chart, lv_palette_main(LV_PALETTE_RED), LV_CHART_AXIS_PRIMARY_Y);
lv_chart_series_t * ser2 = lv_chart_add_series(chart, lv_palette_main(LV_PALETTE_GREEN), LV_CHART_AXIS_PRIMARY_Y);
uint32_t i;
for(i = 0; i < 10; i++) {
lv_chart_set_next_value(chart, ser1, lv_rand(60, 90));
lv_chart_set_next_value(chart, ser2, lv_rand(10, 40));
}
}
#endif
def event_cb(e):
code = e.get_code()
chart = e.get_target()
if code == lv.EVENT.VALUE_CHANGED:
chart.invalidate()
if code == lv.EVENT.REFR_EXT_DRAW_SIZE:
e.set_ext_draw_size(20)
elif code == lv.EVENT.DRAW_POST_END:
id = lv.chart.get_pressed_point(chart)
if id == lv.CHART_POINT.NONE:
return
# print("Selected point ", id)
for i in range(len(series)):
p = lv.point_t()
chart.get_point_pos_by_id(series[i], id, p)
value = series_points[i][id]
buf = lv.SYMBOL.DUMMY + "$" + str(value)
draw_rect_dsc = lv.draw_rect_dsc_t()
draw_rect_dsc.init()
draw_rect_dsc.bg_color = lv.color_black()
draw_rect_dsc.bg_opa = lv.OPA._50
draw_rect_dsc.radius = 3
draw_rect_dsc.bg_img_src = buf
draw_rect_dsc.bg_img_recolor = lv.color_white()
a = lv.area_t()
coords = lv.area_t()
chart.get_coords(coords)
a.x1 = coords.x1 + p.x - 20
a.x2 = coords.x1 + p.x + 20
a.y1 = coords.y1 + p.y - 30
a.y2 = coords.y1 + p.y - 10
clip_area = lv.area_t.__cast__(e.get_param())
lv.draw_rect(a, clip_area, draw_rect_dsc)
elif code == lv.EVENT.RELEASED:
chart.invalidate()
#
# Add ticks and labels to the axis and demonstrate scrolling
#
# Create a chart
chart = lv.chart(lv.scr_act())
chart.set_size(200, 150)
chart.center()
chart.add_event_cb(event_cb, lv.EVENT.ALL, None)
chart.refresh_ext_draw_size()
# Zoom in a little in X
chart.set_zoom_x(800)
# Add two data series
ser1 = chart.add_series(lv.palette_main(lv.PALETTE.RED), lv.chart.AXIS.PRIMARY_Y)
ser2 = chart.add_series(lv.palette_main(lv.PALETTE.GREEN), lv.chart.AXIS.PRIMARY_Y)
ser1_p = []
ser2_p = []
for i in range(10):
ser1_p.append(lv.rand(60,90))
ser2_p.append(lv.rand(10,40))
ser1.y_points = ser1_p
ser2.y_points = ser2_p
series = [ser1,ser2]
series_points=[ser1_p,ser2_p]
显示 1000 个数据点并支持缩放和滚动¶
C code
GitHub#include "../../lv_examples.h"
#if LV_USE_CHART && LV_USE_SLIDER && LV_BUILD_EXAMPLES
static lv_obj_t * chart;
/* Source: https://github.com/ankur219/ECG-Arrhythmia-classification/blob/642230149583adfae1e4bd26c6f0e1fd8af2be0e/sample.csv*/
static const lv_coord_t ecg_sample[] = {
-2, 2, 0, -15, -39, -63, -71, -68, -67, -69, -84, -95, -104, -107, -108, -107, -107, -107, -107, -114, -118, -117,
-112, -100, -89, -83, -71, -64, -58, -58, -62, -62, -58, -51, -46, -39, -27, -10, 4, 7, 1, -3, 0, 14, 24, 30, 25, 19,
13, 7, 12, 15, 18, 21, 13, 6, 9, 8, 17, 19, 13, 11, 11, 11, 23, 30, 37, 34, 25, 14, 15, 19, 28, 31, 26, 23, 25, 31,
39, 37, 37, 34, 30, 32, 22, 29, 31, 33, 37, 23, 13, 7, 2, 4, -2, 2, 11, 22, 33, 19, -1, -27, -55, -67, -72, -71, -63,
-49, -18, 35, 113, 230, 369, 525, 651, 722, 730, 667, 563, 454, 357, 305, 288, 274, 255, 212, 173, 143, 117, 82, 39,
-13, -53, -78, -91, -101, -113, -124, -131, -131, -131, -129, -128, -129, -125, -123, -123, -129, -139, -148, -153,
-159, -166, -183, -205, -227, -243, -248, -246, -254, -280, -327, -381, -429, -473, -517, -556, -592, -612, -620,
-620, -614, -604, -591, -574, -540, -497, -441, -389, -358, -336, -313, -284, -222, -167, -114, -70, -47, -28, -4, 12,
38, 52, 58, 56, 56, 57, 68, 77, 86, 86, 80, 69, 67, 70, 82, 85, 89, 90, 89, 89, 88, 91, 96, 97, 91, 83, 78, 82, 88, 95,
96, 105, 106, 110, 102, 100, 96, 98, 97, 101, 98, 99, 100, 107, 113, 119, 115, 110, 96, 85, 73, 64, 69, 76, 79,
78, 75, 85, 100, 114, 113, 105, 96, 84, 74, 66, 60, 75, 85, 89, 83, 67, 61, 67, 73, 79, 74, 63, 57, 56, 58, 61, 55,
48, 45, 46, 55, 62, 55, 49, 43, 50, 59, 63, 57, 40, 31, 23, 25, 27, 31, 35, 34, 30, 36, 34, 42, 38, 36, 40, 46, 50,
47, 32, 30, 32, 52, 67, 73, 71, 63, 54, 53, 45, 41, 28, 13, 3, 1, 4, 4, -8, -23, -32, -31, -19, -5, 3, 9, 13, 19,
24, 27, 29, 25, 22, 26, 32, 42, 51, 56, 60, 57, 55, 53, 53, 54, 59, 54, 49, 26, -3, -11, -20, -47, -100, -194, -236,
-212, -123, 8, 103, 142, 147, 120, 105, 98, 93, 81, 61, 40, 26, 28, 30, 30, 27, 19, 17, 21, 20, 19, 19, 22, 36, 40,
35, 20, 7, 1, 10, 18, 27, 22, 6, -4, -2, 3, 6, -2, -13, -14, -10, -2, 3, 2, -1, -5, -10, -19, -32, -42, -55, -60,
-68, -77, -86, -101, -110, -117, -115, -104, -92, -84, -85, -84, -73, -65, -52, -50, -45, -35, -20, -3, 12, 20, 25,
26, 28, 28, 30, 28, 25, 28, 33, 42, 42, 36, 23, 9, 0, 1, -4, 1, -4, -4, 1, 5, 9, 9, -3, -1, -18, -50, -108, -190,
-272, -340, -408, -446, -537, -643, -777, -894, -920, -853, -697, -461, -251, -60, 58, 103, 129, 139, 155, 170, 173,
178, 185, 190, 193, 200, 208, 215, 225, 224, 232, 234, 240, 240, 236, 229, 226, 224, 232, 233, 232, 224, 219, 219,
223, 231, 226, 223, 219, 218, 223, 223, 223, 233, 245, 268, 286, 296, 295, 283, 271, 263, 252, 243, 226, 210, 197,
186, 171, 152, 133, 117, 114, 110, 107, 96, 80, 63, 48, 40, 38, 34, 28, 15, 2, -7, -11, -14, -18, -29, -37, -44, -50,
-58, -63, -61, -52, -50, -48, -61, -59, -58, -54, -47, -52, -62, -61, -64, -54, -52, -59, -69, -76, -76, -69, -67,
-74, -78, -81, -80, -73, -65, -57, -53, -51, -47, -35, -27, -22, -22, -24, -21, -17, -13, -10, -11, -13, -20, -20,
-12, -2, 7, -1, -12, -16, -13, -2, 2, -4, -5, -2, 9, 19, 19, 14, 11, 13, 19, 21, 20, 18, 19, 19, 19, 16, 15, 13, 14,
9, 3, -5, -9, -5, -3, -2, -3, -3, 2, 8, 9, 9, 5, 6, 8, 8, 7, 4, 3, 4, 5, 3, 5, 5, 13, 13, 12, 10, 10, 15, 22, 17,
14, 7, 10, 15, 16, 11, 12, 10, 13, 9, -2, -4, -2, 7, 16, 16, 17, 16, 7, -1, -16, -18, -16, -9, -4, -5, -10, -9, -8,
-3, -4, -10, -19, -20, -16, -9, -9, -23, -40, -48, -43, -33, -19, -21, -26, -31, -33, -19, 0, 17, 24, 9, -17, -47,
-63, -67, -59, -52, -51, -50, -49, -42, -26, -21, -15, -20, -23, -22, -19, -12, -8, 5, 18, 27, 32, 26, 25, 26, 22,
23, 17, 14, 17, 21, 25, 2, -45, -121, -196, -226, -200, -118, -9, 73, 126, 131, 114, 87, 60, 42, 29, 26, 34, 35, 34,
25, 12, 9, 7, 3, 2, -8, -11, 2, 23, 38, 41, 23, 9, 10, 13, 16, 8, -8, -17, -23, -26, -25, -21, -15, -10, -13, -13,
-19, -22, -29, -40, -48, -48, -54, -55, -66, -82, -85, -90, -92, -98, -114, -119, -124, -129, -132, -146, -146, -138,
-124, -99, -85, -72, -65, -65, -65, -66, -63, -64, -64, -58, -46, -26, -9, 2, 2, 4, 0, 1, 4, 3, 10, 11, 10, 2, -4,
0, 10, 18, 20, 6, 2, -9, -7, -3, -3, -2, -7, -12, -5, 5, 24, 36, 31, 25, 6, 3, 7, 12, 17, 11, 0, -6, -9, -8, -7, -5,
-6, -2, -2, -6, -2, 2, 14, 24, 22, 15, 8, 4, 6, 7, 12, 16, 25, 20, 7, -16, -41, -60, -67, -65, -54, -35, -11, 30,
84, 175, 302, 455, 603, 707, 743, 714, 625, 519, 414, 337, 300, 281, 263, 239, 197, 163, 136, 109, 77, 34, -18, -50,
-66, -74, -79, -92, -107, -117, -127, -129, -135, -139, -141, -155, -159, -167, -171, -169, -174, -175, -178, -191,
-202, -223, -235, -243, -237, -240, -256, -298, -345, -393, -432, -475, -518, -565, -596, -619, -623, -623, -614,
-599, -583, -559, -524, -477, -425, -383, -357, -331, -301, -252, -198, -143, -96, -57, -29, -8, 10, 31, 45, 60, 65,
70, 74, 76, 79, 82, 79, 75, 62,
};
static void slider_x_event_cb(lv_event_t * e)
{
lv_obj_t * obj = lv_event_get_target(e);
int32_t v = lv_slider_get_value(obj);
lv_chart_set_zoom_x(chart, v);
}
static void slider_y_event_cb(lv_event_t * e)
{
lv_obj_t * obj = lv_event_get_target(e);
int32_t v = lv_slider_get_value(obj);
lv_chart_set_zoom_y(chart, v);
}
/**
* Display 1000 data points with zooming and scrolling.
* See how the chart changes drawing mode (draw only vertical lines) when
* the points get too crowded.
*/
void lv_example_chart_5(void)
{
/*Create a chart*/
chart = lv_chart_create(lv_scr_act());
lv_obj_set_size(chart, 200, 150);
lv_obj_align(chart, LV_ALIGN_CENTER, -30, -30);
lv_chart_set_range(chart, LV_CHART_AXIS_PRIMARY_Y, -1000, 1000);
/*Do not display points on the data*/
lv_obj_set_style_size(chart, 0, LV_PART_INDICATOR);
lv_chart_series_t * ser = lv_chart_add_series(chart, lv_palette_main(LV_PALETTE_RED), LV_CHART_AXIS_PRIMARY_Y);
uint32_t pcnt = sizeof(ecg_sample) / sizeof(ecg_sample[0]);
lv_chart_set_point_count(chart, pcnt);
lv_chart_set_ext_y_array(chart, ser, (lv_coord_t *)ecg_sample);
lv_obj_t * slider;
slider = lv_slider_create(lv_scr_act());
lv_slider_set_range(slider, LV_IMG_ZOOM_NONE, LV_IMG_ZOOM_NONE * 10);
lv_obj_add_event_cb(slider, slider_x_event_cb, LV_EVENT_VALUE_CHANGED, NULL);
lv_obj_set_size(slider, 200, 10);
lv_obj_align_to(slider, chart, LV_ALIGN_OUT_BOTTOM_MID, 0, 20);
slider = lv_slider_create(lv_scr_act());
lv_slider_set_range(slider, LV_IMG_ZOOM_NONE, LV_IMG_ZOOM_NONE * 10);
lv_obj_add_event_cb(slider, slider_y_event_cb, LV_EVENT_VALUE_CHANGED, NULL);
lv_obj_set_size(slider, 10, 150);
lv_obj_align_to(slider, chart, LV_ALIGN_OUT_RIGHT_MID, 20, 0);
}
#endif
# Source: https://github.com/ankur219/ECG-Arrhythmia-classification/blob/642230149583adfae1e4bd26c6f0e1fd8af2be0e/sample.csv
ecg_sample = [
-2, 2, 0, -15, -39, -63, -71, -68, -67, -69, -84, -95, -104, -107, -108, -107, -107, -107, -107, -114, -118, -117,
-112, -100, -89, -83, -71, -64, -58, -58, -62, -62, -58, -51, -46, -39, -27, -10, 4, 7, 1, -3, 0, 14, 24, 30, 25, 19,
13, 7, 12, 15, 18, 21, 13, 6, 9, 8, 17, 19, 13, 11, 11, 11, 23, 30, 37, 34, 25, 14, 15, 19, 28, 31, 26, 23, 25, 31,
39, 37, 37, 34, 30, 32, 22, 29, 31, 33, 37, 23, 13, 7, 2, 4, -2, 2, 11, 22, 33, 19, -1, -27, -55, -67, -72, -71, -63,
-49, -18, 35, 113, 230, 369, 525, 651, 722, 730, 667, 563, 454, 357, 305, 288, 274, 255, 212, 173, 143, 117, 82, 39,
-13, -53, -78, -91, -101, -113, -124, -131, -131, -131, -129, -128, -129, -125, -123, -123, -129, -139, -148, -153,
-159, -166, -183, -205, -227, -243, -248, -246, -254, -280, -327, -381, -429, -473, -517, -556, -592, -612, -620,
-620, -614, -604, -591, -574, -540, -497, -441, -389, -358, -336, -313, -284, -222, -167, -114, -70, -47, -28, -4, 12,
38, 52, 58, 56, 56, 57, 68, 77, 86, 86, 80, 69, 67, 70, 82, 85, 89, 90, 89, 89, 88, 91, 96, 97, 91, 83, 78, 82, 88, 95,
96, 105, 106, 110, 102, 100, 96, 98, 97, 101, 98, 99, 100, 107, 113, 119, 115, 110, 96, 85, 73, 64, 69, 76, 79,
78, 75, 85, 100, 114, 113, 105, 96, 84, 74, 66, 60, 75, 85, 89, 83, 67, 61, 67, 73, 79, 74, 63, 57, 56, 58, 61, 55,
48, 45, 46, 55, 62, 55, 49, 43, 50, 59, 63, 57, 40, 31, 23, 25, 27, 31, 35, 34, 30, 36, 34, 42, 38, 36, 40, 46, 50,
47, 32, 30, 32, 52, 67, 73, 71, 63, 54, 53, 45, 41, 28, 13, 3, 1, 4, 4, -8, -23, -32, -31, -19, -5, 3, 9, 13, 19,
24, 27, 29, 25, 22, 26, 32, 42, 51, 56, 60, 57, 55, 53, 53, 54, 59, 54, 49, 26, -3, -11, -20, -47, -100, -194, -236,
-212, -123, 8, 103, 142, 147, 120, 105, 98, 93, 81, 61, 40, 26, 28, 30, 30, 27, 19, 17, 21, 20, 19, 19, 22, 36, 40,
35, 20, 7, 1, 10, 18, 27, 22, 6, -4, -2, 3, 6, -2, -13, -14, -10, -2, 3, 2, -1, -5, -10, -19, -32, -42, -55, -60,
-68, -77, -86, -101, -110, -117, -115, -104, -92, -84, -85, -84, -73, -65, -52, -50, -45, -35, -20, -3, 12, 20, 25,
26, 28, 28, 30, 28, 25, 28, 33, 42, 42, 36, 23, 9, 0, 1, -4, 1, -4, -4, 1, 5, 9, 9, -3, -1, -18, -50, -108, -190,
-272, -340, -408, -446, -537, -643, -777, -894, -920, -853, -697, -461, -251, -60, 58, 103, 129, 139, 155, 170, 173,
178, 185, 190, 193, 200, 208, 215, 225, 224, 232, 234, 240, 240, 236, 229, 226, 224, 232, 233, 232, 224, 219, 219,
223, 231, 226, 223, 219, 218, 223, 223, 223, 233, 245, 268, 286, 296, 295, 283, 271, 263, 252, 243, 226, 210, 197,
186, 171, 152, 133, 117, 114, 110, 107, 96, 80, 63, 48, 40, 38, 34, 28, 15, 2, -7, -11, -14, -18, -29, -37, -44, -50,
-58, -63, -61, -52, -50, -48, -61, -59, -58, -54, -47, -52, -62, -61, -64, -54, -52, -59, -69, -76, -76, -69, -67,
-74, -78, -81, -80, -73, -65, -57, -53, -51, -47, -35, -27, -22, -22, -24, -21, -17, -13, -10, -11, -13, -20, -20,
-12, -2, 7, -1, -12, -16, -13, -2, 2, -4, -5, -2, 9, 19, 19, 14, 11, 13, 19, 21, 20, 18, 19, 19, 19, 16, 15, 13, 14,
9, 3, -5, -9, -5, -3, -2, -3, -3, 2, 8, 9, 9, 5, 6, 8, 8, 7, 4, 3, 4, 5, 3, 5, 5, 13, 13, 12, 10, 10, 15, 22, 17,
14, 7, 10, 15, 16, 11, 12, 10, 13, 9, -2, -4, -2, 7, 16, 16, 17, 16, 7, -1, -16, -18, -16, -9, -4, -5, -10, -9, -8,
-3, -4, -10, -19, -20, -16, -9, -9, -23, -40, -48, -43, -33, -19, -21, -26, -31, -33, -19, 0, 17, 24, 9, -17, -47,
-63, -67, -59, -52, -51, -50, -49, -42, -26, -21, -15, -20, -23, -22, -19, -12, -8, 5, 18, 27, 32, 26, 25, 26, 22,
23, 17, 14, 17, 21, 25, 2, -45, -121, -196, -226, -200, -118, -9, 73, 126, 131, 114, 87, 60, 42, 29, 26, 34, 35, 34,
25, 12, 9, 7, 3, 2, -8, -11, 2, 23, 38, 41, 23, 9, 10, 13, 16, 8, -8, -17, -23, -26, -25, -21, -15, -10, -13, -13,
-19, -22, -29, -40, -48, -48, -54, -55, -66, -82, -85, -90, -92, -98, -114, -119, -124, -129, -132, -146, -146, -138,
-124, -99, -85, -72, -65, -65, -65, -66, -63, -64, -64, -58, -46, -26, -9, 2, 2, 4, 0, 1, 4, 3, 10, 11, 10, 2, -4,
0, 10, 18, 20, 6, 2, -9, -7, -3, -3, -2, -7, -12, -5, 5, 24, 36, 31, 25, 6, 3, 7, 12, 17, 11, 0, -6, -9, -8, -7, -5,
-6, -2, -2, -6, -2, 2, 14, 24, 22, 15, 8, 4, 6, 7, 12, 16, 25, 20, 7, -16, -41, -60, -67, -65, -54, -35, -11, 30,
84, 175, 302, 455, 603, 707, 743, 714, 625, 519, 414, 337, 300, 281, 263, 239, 197, 163, 136, 109, 77, 34, -18, -50,
-66, -74, -79, -92, -107, -117, -127, -129, -135, -139, -141, -155, -159, -167, -171, -169, -174, -175, -178, -191,
-202, -223, -235, -243, -237, -240, -256, -298, -345, -393, -432, -475, -518, -565, -596, -619, -623, -623, -614,
-599, -583, -559, -524, -477, -425, -383, -357, -331, -301, -252, -198, -143, -96, -57, -29, -8, 10, 31, 45, 60, 65,
70, 74, 76, 79, 82, 79, 75, 62,
]
def slider_x_event_cb(e):
slider = e.get_target()
v = slider.get_value()
chart.set_zoom_x(v)
def slider_y_event_cb(e):
slider = e.get_target()
v = slider.get_value()
chart.set_zoom_y(v)
#
# Display 1000 data points with zooming and scrolling.
# See how the chart changes drawing mode (draw only vertical lines) when
# the points get too crowded.
# Create a chart
chart = lv.chart(lv.scr_act())
chart.set_size(200, 150)
chart.align(lv.ALIGN.CENTER, -30, -30)
chart.set_range(lv.chart.AXIS.PRIMARY_Y, -1000, 1000)
# Do not display points on the data
chart.set_style_size(0, lv.PART.INDICATOR)
ser = chart.add_series(lv.palette_main(lv.PALETTE.RED), lv.chart.AXIS.PRIMARY_Y)
pcnt = len(ecg_sample)
chart.set_point_count(pcnt)
chart.set_ext_y_array(ser, ecg_sample)
slider = lv.slider(lv.scr_act())
slider.set_range(lv.IMG_ZOOM.NONE, lv.IMG_ZOOM.NONE * 10)
slider.add_event_cb(slider_x_event_cb, lv.EVENT.VALUE_CHANGED, None)
slider.set_size(200,10)
slider.align_to(chart, lv.ALIGN.OUT_BOTTOM_MID, 0, 20)
slider = lv.slider(lv.scr_act())
slider.set_range(lv.IMG_ZOOM.NONE, lv.IMG_ZOOM.NONE * 10)
slider.add_event_cb(slider_y_event_cb, lv.EVENT.VALUE_CHANGED, None)
slider.set_size(10, 150)
slider.align_to(chart, lv.ALIGN.OUT_RIGHT_MID, 20, 0)
在点击点上显示光标¶
C code
GitHub#include "../../lv_examples.h"
#if LV_USE_CHART && LV_BUILD_EXAMPLES
static lv_obj_t * chart;
static lv_chart_series_t * ser;
static lv_chart_cursor_t * cursor;
static void event_cb(lv_event_t * e)
{
static int32_t last_id = -1;
lv_event_code_t code = lv_event_get_code(e);
lv_obj_t * obj = lv_event_get_target(e);
if(code == LV_EVENT_VALUE_CHANGED) {
last_id = lv_chart_get_pressed_point(obj);
if(last_id != LV_CHART_POINT_NONE) {
lv_chart_set_cursor_point(obj, cursor, NULL, last_id);
}
}
else if(code == LV_EVENT_DRAW_PART_END) {
lv_obj_draw_part_dsc_t * dsc = lv_event_get_draw_part_dsc(e);
if(!lv_obj_draw_part_check_type(dsc, &lv_chart_class, LV_CHART_DRAW_PART_CURSOR)) return;
if(dsc->p1 == NULL || dsc->p2 == NULL || dsc->p1->y != dsc->p2->y || last_id < 0) return;
lv_coord_t * data_array = lv_chart_get_y_array(chart, ser);
lv_coord_t v = data_array[last_id];
char buf[16];
lv_snprintf(buf, sizeof(buf), "%d", v);
lv_point_t size;
lv_txt_get_size(&size, buf, LV_FONT_DEFAULT, 0, 0, LV_COORD_MAX, LV_TEXT_FLAG_NONE);
lv_area_t a;
a.y2 = dsc->p1->y - 5;
a.y1 = a.y2 - size.y - 10;
a.x1 = dsc->p1->x + 10;
a.x2 = a.x1 + size.x + 10;
lv_draw_rect_dsc_t draw_rect_dsc;
lv_draw_rect_dsc_init(&draw_rect_dsc);
draw_rect_dsc.bg_color = lv_palette_main(LV_PALETTE_BLUE);
draw_rect_dsc.radius = 3;
lv_draw_rect(dsc->draw_ctx, &draw_rect_dsc, &a);
lv_draw_label_dsc_t draw_label_dsc;
lv_draw_label_dsc_init(&draw_label_dsc);
draw_label_dsc.color = lv_color_white();
a.x1 += 5;
a.x2 -= 5;
a.y1 += 5;
a.y2 -= 5;
lv_draw_label(dsc->draw_ctx, &draw_label_dsc, &a, buf, NULL);
}
}
/**
* Show cursor on the clicked point
*/
void lv_example_chart_6(void)
{
chart = lv_chart_create(lv_scr_act());
lv_obj_set_size(chart, 200, 150);
lv_obj_align(chart, LV_ALIGN_CENTER, 0, -10);
lv_chart_set_axis_tick(chart, LV_CHART_AXIS_PRIMARY_Y, 10, 5, 6, 5, true, 40);
lv_chart_set_axis_tick(chart, LV_CHART_AXIS_PRIMARY_X, 10, 5, 10, 1, true, 30);
lv_obj_add_event_cb(chart, event_cb, LV_EVENT_ALL, NULL);
lv_obj_refresh_ext_draw_size(chart);
cursor = lv_chart_add_cursor(chart, lv_palette_main(LV_PALETTE_BLUE), LV_DIR_LEFT | LV_DIR_BOTTOM);
ser = lv_chart_add_series(chart, lv_palette_main(LV_PALETTE_RED), LV_CHART_AXIS_PRIMARY_Y);
uint32_t i;
for(i = 0; i < 10; i++) {
lv_chart_set_next_value(chart, ser, lv_rand(10, 90));
}
lv_chart_set_zoom_x(chart, 500);
lv_obj_t * label = lv_label_create(lv_scr_act());
lv_label_set_text(label, "Click on a point");
lv_obj_align_to(label, chart, LV_ALIGN_OUT_TOP_MID, 0, -5);
}
#endif
class ExampleChart_6():
def __init__(self):
self.last_id = -1
#
# Show cursor on the clicked point
#
chart = lv.chart(lv.scr_act())
chart.set_size(200, 150)
chart.align(lv.ALIGN.CENTER, 0, -10)
chart.set_axis_tick(lv.chart.AXIS.PRIMARY_Y, 10, 5, 6, 5, True, 40)
chart.set_axis_tick(lv.chart.AXIS.PRIMARY_X, 10, 5, 10, 1, True, 30)
chart.add_event_cb(self.event_cb, lv.EVENT.ALL, None)
chart.refresh_ext_draw_size()
self.cursor = chart.add_cursor(lv.palette_main(lv.PALETTE.BLUE), lv.DIR.LEFT | lv.DIR.BOTTOM)
self.ser = chart.add_series(lv.palette_main(lv.PALETTE.RED), lv.chart.AXIS.PRIMARY_Y)
self.ser_p = []
for i in range(10):
self.ser_p.append(lv.rand(10,90))
self.ser.y_points = self.ser_p
newser = chart.get_series_next(None)
# print("length of data points: ",len(newser.points))
chart.set_zoom_x(500)
label = lv.label(lv.scr_act())
label.set_text("Click on a point")
label.align_to(chart, lv.ALIGN.OUT_TOP_MID, 0, -5)
def event_cb(self,e):
code = e.get_code()
chart = e.get_target()
if code == lv.EVENT.VALUE_CHANGED:
# print("last_id: ",self.last_id)
self.last_id = chart.get_pressed_point()
if self.last_id != lv.CHART_POINT.NONE:
p = lv.point_t()
chart.get_point_pos_by_id(self.ser, self.last_id, p)
chart.set_cursor_point(self.cursor, None, self.last_id)
elif code == lv.EVENT.DRAW_PART_END:
# print("EVENT.DRAW_PART_END")
dsc = lv.obj_draw_part_dsc_t.__cast__(e.get_param())
# if dsc.p1 and dsc.p2:
# print("p1, p2", dsc.p1,dsc.p2)
# print("p1.y, p2.y", dsc.p1.y, dsc.p2.y)
# print("last_id: ",self.last_id)
if dsc.part == lv.PART.CURSOR and dsc.p1 and dsc.p2 and dsc.p1.y == dsc.p2.y and self.last_id >= 0:
v = self.ser_p[self.last_id]
# print("value: ",v)
value_txt = str(v)
size = lv.point_t()
lv.txt_get_size(size, value_txt, lv.font_default(), 0, 0, lv.COORD.MAX, lv.TEXT_FLAG.NONE)
a = lv.area_t()
a.y2 = dsc.p1.y - 5
a.y1 = a.y2 - size.y - 10
a.x1 = dsc.p1.x + 10
a.x2 = a.x1 + size.x + 10
draw_rect_dsc = lv.draw_rect_dsc_t()
draw_rect_dsc.init()
draw_rect_dsc.bg_color = lv.palette_main(lv.PALETTE.BLUE)
draw_rect_dsc.radius = 3
lv.draw_rect(a, dsc.clip_area, draw_rect_dsc)
draw_label_dsc = lv.draw_label_dsc_t()
draw_label_dsc.init()
draw_label_dsc.color = lv.color_white()
a.x1 += 5
a.x2 -= 5
a.y1 += 5
a.y2 -= 5
lv.draw_label(a, dsc.clip_area, draw_label_dsc, value_txt, None)
example_chart_6 = ExampleChart_6()
散点图¶
C code
GitHub#include "../../lv_examples.h"
#if LV_USE_CHART && LV_BUILD_EXAMPLES
static void draw_event_cb(lv_event_t * e)
{
lv_obj_draw_part_dsc_t * dsc = lv_event_get_draw_part_dsc(e);
if(dsc->part == LV_PART_ITEMS) {
lv_obj_t * obj = lv_event_get_target(e);
lv_chart_series_t * ser = lv_chart_get_series_next(obj, NULL);
uint32_t cnt = lv_chart_get_point_count(obj);
/*Make older value more transparent*/
dsc->rect_dsc->bg_opa = (LV_OPA_COVER * dsc->id) / (cnt - 1);
/*Make smaller values blue, higher values red*/
lv_coord_t * x_array = lv_chart_get_x_array(obj, ser);
lv_coord_t * y_array = lv_chart_get_y_array(obj, ser);
/*dsc->id is the tells drawing order, but we need the ID of the point being drawn.*/
uint32_t start_point = lv_chart_get_x_start_point(obj, ser);
uint32_t p_act = (start_point + dsc->id) % cnt; /*Consider start point to get the index of the array*/
lv_opa_t x_opa = (x_array[p_act] * LV_OPA_50) / 200;
lv_opa_t y_opa = (y_array[p_act] * LV_OPA_50) / 1000;
dsc->rect_dsc->bg_color = lv_color_mix(lv_palette_main(LV_PALETTE_RED),
lv_palette_main(LV_PALETTE_BLUE),
x_opa + y_opa);
}
}
static void add_data(lv_timer_t * timer)
{
LV_UNUSED(timer);
lv_obj_t * chart = timer->user_data;
lv_chart_set_next_value2(chart, lv_chart_get_series_next(chart, NULL), lv_rand(0, 200), lv_rand(0, 1000));
}
/**
* A scatter chart
*/
void lv_example_chart_7(void)
{
lv_obj_t * chart = lv_chart_create(lv_scr_act());
lv_obj_set_size(chart, 200, 150);
lv_obj_align(chart, LV_ALIGN_CENTER, 0, 0);
lv_obj_add_event_cb(chart, draw_event_cb, LV_EVENT_DRAW_PART_BEGIN, NULL);
lv_obj_set_style_line_width(chart, 0, LV_PART_ITEMS); /*Remove the lines*/
lv_chart_set_type(chart, LV_CHART_TYPE_SCATTER);
lv_chart_set_axis_tick(chart, LV_CHART_AXIS_PRIMARY_X, 5, 5, 5, 1, true, 30);
lv_chart_set_axis_tick(chart, LV_CHART_AXIS_PRIMARY_Y, 10, 5, 6, 5, true, 50);
lv_chart_set_range(chart, LV_CHART_AXIS_PRIMARY_X, 0, 200);
lv_chart_set_range(chart, LV_CHART_AXIS_PRIMARY_Y, 0, 1000);
lv_chart_set_point_count(chart, 50);
lv_chart_series_t * ser = lv_chart_add_series(chart, lv_palette_main(LV_PALETTE_RED), LV_CHART_AXIS_PRIMARY_Y);
uint32_t i;
for(i = 0; i < 50; i++) {
lv_chart_set_next_value2(chart, ser, lv_rand(0, 200), lv_rand(0, 1000));
}
lv_timer_create(add_data, 100, chart);
}
#endif
#!/opt/bin/lv_micropython -i
import utime as time
import lvgl as lv
import display_driver
def draw_event_cb(e):
dsc = e.get_draw_part_dsc()
if dsc.part == lv.PART.ITEMS:
obj = e.get_target()
ser = obj.get_series_next(None)
cnt = obj.get_point_count()
# print("cnt: ",cnt)
# Make older value more transparent
dsc.rect_dsc.bg_opa = (lv.OPA.COVER * dsc.id) // (cnt - 1)
# Make smaller values blue, higher values red
# x_array = chart.get_x_array(ser)
# y_array = chart.get_y_array(ser)
# dsc->id is the tells drawing order, but we need the ID of the point being drawn.
start_point = chart.get_x_start_point(ser)
# print("start point: ",start_point)
p_act = (start_point + dsc.id) % cnt # Consider start point to get the index of the array
# print("p_act", p_act)
x_opa = (x_array[p_act] * lv.OPA._50) // 200
y_opa = (y_array[p_act] * lv.OPA._50) // 1000
dsc.rect_dsc.bg_color = lv.palette_main(lv.PALETTE.RED).color_mix(
lv.palette_main(lv.PALETTE.BLUE),
x_opa + y_opa)
def add_data(timer,chart):
# print("add_data")
x = lv.rand(0,200)
y = lv.rand(0,1000)
chart.set_next_value2(ser, x, y)
# chart.set_next_value2(chart.gx, y)
x_array.pop(0)
x_array.append(x)
y_array.pop(0)
y_array.append(y)
#
# A scatter chart
#
chart = lv.chart(lv.scr_act())
chart.set_size(200, 150)
chart.align(lv.ALIGN.CENTER, 0, 0)
chart.add_event_cb(draw_event_cb, lv.EVENT.DRAW_PART_BEGIN, None)
chart.set_style_line_width(0, lv.PART.ITEMS) # Remove the lines
chart.set_type(lv.chart.TYPE.SCATTER)
chart.set_axis_tick(lv.chart.AXIS.PRIMARY_X, 5, 5, 5, 1, True, 30)
chart.set_axis_tick(lv.chart.AXIS.PRIMARY_Y, 10, 5, 6, 5, True, 50)
chart.set_range(lv.chart.AXIS.PRIMARY_X, 0, 200)
chart.set_range(lv.chart.AXIS.PRIMARY_Y, 0, 1000)
chart.set_point_count(50)
ser = chart.add_series(lv.palette_main(lv.PALETTE.RED), lv.chart.AXIS.PRIMARY_Y)
x_array = []
y_array = []
for i in range(50):
x_array.append(lv.rand(0, 200))
y_array.append(lv.rand(0, 1000))
ser.x_points = x_array
ser.y_points = y_array
# Create an `lv_timer` to update the chart.
timer = lv.timer_create_basic()
timer.set_period(100)
timer.set_cb(lambda src: add_data(timer,chart))
堆叠区域图¶
C code
GitHub#include "../../lv_examples.h"
#if LV_USE_CHART && LV_DRAW_COMPLEX && LV_BUILD_EXAMPLES
/* A struct is used to keep track of the series list because later we need to draw to the series in the reverse order to which they were initialised. */
typedef struct {
lv_obj_t * obj;
lv_chart_series_t * series_list[3];
} stacked_area_chart_t;
static stacked_area_chart_t stacked_area_chart;
/**
* Callback which draws the blocks of colour under the lines
**/
static void draw_event_cb(lv_event_t * e)
{
lv_obj_t * obj = lv_event_get_target(e);
/*Add the faded area before the lines are drawn*/
lv_obj_draw_part_dsc_t * dsc = lv_event_get_draw_part_dsc(e);
if(dsc->part == LV_PART_ITEMS) {
if(!dsc->p1 || !dsc->p2)
return;
/*Add a line mask that keeps the area below the line*/
lv_draw_mask_line_param_t line_mask_param;
lv_draw_mask_line_points_init(&line_mask_param, dsc->p1->x, dsc->p1->y, dsc->p2->x, dsc->p2->y,
LV_DRAW_MASK_LINE_SIDE_BOTTOM);
int16_t line_mask_id = lv_draw_mask_add(&line_mask_param, NULL);
/*Draw a rectangle that will be affected by the mask*/
lv_draw_rect_dsc_t draw_rect_dsc;
lv_draw_rect_dsc_init(&draw_rect_dsc);
draw_rect_dsc.bg_opa = LV_OPA_COVER;
draw_rect_dsc.bg_color = dsc->line_dsc->color;
lv_area_t a;
a.x1 = dsc->p1->x;
a.x2 = dsc->p2->x;
a.y1 = LV_MIN(dsc->p1->y, dsc->p2->y);
a.y2 = obj->coords.y2 -
13; /* -13 cuts off where the rectangle draws over the chart margin. Without this an area of 0 doesn't look like 0 */
lv_draw_rect(dsc->draw_ctx, &draw_rect_dsc, &a);
/*Remove the mask*/
lv_draw_mask_free_param(&line_mask_param);
lv_draw_mask_remove_id(line_mask_id);
}
}
/**
* Helper function to round a fixed point number
**/
static int32_t round_fixed_point(int32_t n, int8_t shift)
{
/* Create a bitmask to isolates the decimal part of the fixed point number */
int32_t mask = 1;
for(int32_t bit_pos = 0; bit_pos < shift; bit_pos++) {
mask = (mask << 1) + 1;
}
int32_t decimal_part = n & mask;
/* Get 0.5 as fixed point */
int32_t rounding_boundary = 1 << (shift - 1);
/* Return either the integer part of n or the integer part + 1 */
return (decimal_part < rounding_boundary) ? (n & ~mask) : ((n >> shift) + 1) << shift;
}
/**
* Stacked area chart
*/
void lv_example_chart_8(void)
{
/*Create a stacked_area_chart.obj*/
stacked_area_chart.obj = lv_chart_create(lv_scr_act());
lv_obj_set_size(stacked_area_chart.obj, 200, 150);
lv_obj_center(stacked_area_chart.obj);
lv_chart_set_type(stacked_area_chart.obj, LV_CHART_TYPE_LINE);
lv_chart_set_div_line_count(stacked_area_chart.obj, 5, 7);
lv_obj_add_event_cb(stacked_area_chart.obj, draw_event_cb, LV_EVENT_DRAW_PART_BEGIN, NULL);
/* Set range to 0 to 100 for percentages. Draw ticks */
lv_chart_set_range(stacked_area_chart.obj, LV_CHART_AXIS_PRIMARY_Y, 0, 100);
lv_chart_set_axis_tick(stacked_area_chart.obj, LV_CHART_AXIS_PRIMARY_Y, 3, 0, 5, 1, true, 30);
/*Set point size to 0 so the lines are smooth */
lv_obj_set_style_size(stacked_area_chart.obj, 0, LV_PART_INDICATOR);
/*Add some data series*/
stacked_area_chart.series_list[0] = lv_chart_add_series(stacked_area_chart.obj, lv_palette_main(LV_PALETTE_RED),
LV_CHART_AXIS_PRIMARY_Y);
stacked_area_chart.series_list[1] = lv_chart_add_series(stacked_area_chart.obj, lv_palette_main(LV_PALETTE_BLUE),
LV_CHART_AXIS_PRIMARY_Y);
stacked_area_chart.series_list[2] = lv_chart_add_series(stacked_area_chart.obj, lv_palette_main(LV_PALETTE_GREEN),
LV_CHART_AXIS_PRIMARY_Y);
for(int point = 0; point < 10; point++) {
/* Make some random data */
uint32_t vals[3] = {lv_rand(10, 20), lv_rand(20, 30), lv_rand(20, 30)};
int8_t fixed_point_shift = 5;
uint32_t total = vals[0] + vals[1] + vals[2];
uint32_t draw_heights[3];
uint32_t int_sum = 0;
uint32_t decimal_sum = 0;
/* Fixed point cascade rounding ensures percentages add to 100 */
for(int32_t series_index = 0; series_index < 3; series_index++) {
decimal_sum += (((vals[series_index] * 100) << fixed_point_shift) / total);
int_sum += (vals[series_index] * 100) / total;
int32_t modifier = (round_fixed_point(decimal_sum, fixed_point_shift) >> fixed_point_shift) - int_sum;
/* The draw heights are equal to the percentage of the total each value is + the cumulative sum of the previous percentages.
The accumulation is how the values get "stacked" */
draw_heights[series_index] = int_sum + modifier;
/* Draw to the series in the reverse order to which they were initialised.
Without this the higher values will draw on top of the lower ones.
This is because the Z-height of a series matches the order it was initialised */
lv_chart_set_next_value(stacked_area_chart.obj, stacked_area_chart.series_list[3 - series_index - 1],
draw_heights[series_index]);
}
}
lv_chart_refresh(stacked_area_chart.obj);
}
#endif
import display_driver
import lvgl as lv
# A class is used to keep track of the series list because later we
# need to draw to the series in the reverse order to which they were initialised.
class StackedAreaChart:
def __init__(self):
self.obj = None
self.series_list = [None, None, None]
stacked_area_chart = StackedAreaChart()
#
# Callback which draws the blocks of colour under the lines
#
def draw_event_cb(e):
obj = e.get_target()
cont_a = lv.area_t()
obj.get_coords(cont_a)
#Add the faded area before the lines are drawn
dsc = e.get_draw_part_dsc()
if dsc.part == lv.PART.ITEMS:
if not dsc.p1 or not dsc.p2:
return
# Add a line mask that keeps the area below the line
line_mask_param = lv.draw_mask_line_param_t()
line_mask_param.points_init(dsc.p1.x, dsc.p1.y, dsc.p2.x, dsc.p2.y, lv.DRAW_MASK_LINE_SIDE.BOTTOM)
line_mask_id = lv.draw_mask_add(line_mask_param, None)
#Draw a rectangle that will be affected by the mask
draw_rect_dsc = lv.draw_rect_dsc_t()
draw_rect_dsc.init()
draw_rect_dsc.bg_opa = lv.OPA.COVER
draw_rect_dsc.bg_color = dsc.line_dsc.color
a = lv.area_t()
a.x1 = dsc.p1.x
a.x2 = dsc.p2.x
a.y1 = min(dsc.p1.y, dsc.p2.y)
a.y2 = cont_a.y2 - 13 # -13 cuts off where the rectangle draws over the chart margin. Without this an area of 0 doesn't look like 0
dsc.draw_ctx.rect(draw_rect_dsc, a)
# Remove the mask
lv.draw_mask_free_param(line_mask_param)
lv.draw_mask_remove_id(line_mask_id)
#
# Helper function to round a fixed point number
#
def round_fixed_point(n, shift):
# Create a bitmask to isolates the decimal part of the fixed point number
mask = 1
for bit_pos in range(shift):
mask = (mask << 1) + 1
decimal_part = n & mask
# Get 0.5 as fixed point
rounding_boundary = 1 << (shift - 1)
# Return either the integer part of n or the integer part + 1
if decimal_part < rounding_boundary:
return (n & ~mask)
return ((n >> shift) + 1) << shift
#
# Stacked area chart
#
def lv_example_chart_8():
#Create a stacked_area_chart.obj
stacked_area_chart.obj = lv.chart(lv.scr_act())
stacked_area_chart.obj.set_size(200, 150)
stacked_area_chart.obj.center()
stacked_area_chart.obj.set_type( lv.chart.TYPE.LINE)
stacked_area_chart.obj.set_div_line_count(5, 7)
stacked_area_chart.obj.add_event_cb( draw_event_cb, lv.EVENT.DRAW_PART_BEGIN, None)
# Set range to 0 to 100 for percentages. Draw ticks
stacked_area_chart.obj.set_range(lv.chart.AXIS.PRIMARY_Y,0,100)
stacked_area_chart.obj.set_axis_tick(lv.chart.AXIS.PRIMARY_Y, 3, 0, 5, 1, True, 30)
#Set point size to 0 so the lines are smooth
stacked_area_chart.obj.set_style_size(0, lv.PART.INDICATOR)
# Add some data series
stacked_area_chart.series_list[0] = stacked_area_chart.obj.add_series(lv.palette_main(lv.PALETTE.RED), lv.chart.AXIS.PRIMARY_Y)
stacked_area_chart.series_list[1] = stacked_area_chart.obj.add_series(lv.palette_main(lv.PALETTE.BLUE), lv.chart.AXIS.PRIMARY_Y)
stacked_area_chart.series_list[2] = stacked_area_chart.obj.add_series(lv.palette_main(lv.PALETTE.GREEN), lv.chart.AXIS.PRIMARY_Y)
for point in range(10):
# Make some random data
vals = [lv.rand(10, 20), lv.rand(20, 30), lv.rand(20, 30)]
fixed_point_shift = 5
total = vals[0] + vals[1] + vals[2]
draw_heights = [0, 0, 0]
int_sum = 0
decimal_sum = 0
# Fixed point cascade rounding ensures percentages add to 100
for series_index in range(3):
decimal_sum += int(((vals[series_index] * 100) << fixed_point_shift) // total)
int_sum += int((vals[series_index] * 100) / total)
modifier = (round_fixed_point(decimal_sum, fixed_point_shift) >> fixed_point_shift) - int_sum
# The draw heights are equal to the percentage of the total each value is + the cumulative sum of the previous percentages.
# The accumulation is how the values get "stacked"
draw_heights[series_index] = int(int_sum + modifier)
# Draw to the series in the reverse order to which they were initialised.
# Without this the higher values will draw on top of the lower ones.
# This is because the Z-height of a series matches the order it was initialised
stacked_area_chart.obj.set_next_value( stacked_area_chart.series_list[3 - series_index - 1], draw_heights[series_index])
stacked_area_chart.obj.refresh()
lv_example_chart_8()
API¶
Typedefs
-
typedef uint8_t
lv_chart_type_t¶
-
typedef uint8_t
lv_chart_update_mode_t¶
-
typedef uint8_t
lv_chart_axis_t¶
Enums
-
Chart types
Values:
-
enumerator
LV_CHART_TYPE_NONE¶ Don't draw the series
-
enumerator
LV_CHART_TYPE_LINE¶ Connect the points with lines
-
enumerator
LV_CHART_TYPE_BAR¶ Draw columns
-
enumerator
LV_CHART_TYPE_SCATTER¶ Draw points and lines in 2D (x,y coordinates)
-
enumerator
-
Chart update mode for
lv_chart_set_nextValues:
-
enumerator
LV_CHART_UPDATE_MODE_SHIFT¶ Shift old data to the left and add the new one the right
-
enumerator
LV_CHART_UPDATE_MODE_CIRCULAR¶ Add the new data in a circular way
-
enumerator
-
Enumeration of the axis'
Values:
-
enumerator
LV_CHART_AXIS_PRIMARY_Y¶
-
enumerator
LV_CHART_AXIS_SECONDARY_Y¶
-
enumerator
LV_CHART_AXIS_PRIMARY_X¶
-
enumerator
LV_CHART_AXIS_SECONDARY_X¶
-
enumerator
_LV_CHART_AXIS_LAST¶
-
enumerator
-
enum
lv_chart_draw_part_type_t¶ typefield inlv_obj_draw_part_dsc_tifclass_p = lv_chart_classUsed inLV_EVENT_DRAW_PART_BEGINandLV_EVENT_DRAW_PART_ENDValues:
-
enumerator
LV_CHART_DRAW_PART_DIV_LINE_INIT¶ Used before/after drawn the div lines
-
enumerator
LV_CHART_DRAW_PART_DIV_LINE_HOR¶ Used for each horizontal division lines
-
enumerator
LV_CHART_DRAW_PART_DIV_LINE_VER¶ Used for each vertical division lines
-
enumerator
LV_CHART_DRAW_PART_LINE_AND_POINT¶ Used on line and scatter charts for lines and points
-
enumerator
LV_CHART_DRAW_PART_BAR¶ Used on bar charts for the rectangles
-
enumerator
LV_CHART_DRAW_PART_CURSOR¶ Used on cursor lines and points
-
enumerator
LV_CHART_DRAW_PART_TICK_LABEL¶ Used on tick lines and labels
-
enumerator
Functions
-
LV_EXPORT_CONST_INT(LV_CHART_POINT_NONE)¶
-
lv_obj_t *
lv_chart_create(lv_obj_t *parent)¶ Create a chart object
- Parameters
parent -- pointer to an object, it will be the parent of the new chart
- Returns
pointer to the created chart
-
void
lv_chart_set_type(lv_obj_t *obj, lv_chart_type_t type)¶ Set a new type for a chart
- Parameters
obj -- pointer to a chart object
type -- new type of the chart (from 'lv_chart_type_t' enum)
-
void
lv_chart_set_point_count(lv_obj_t *obj, uint16_t cnt)¶ Set the number of points on a data line on a chart
- Parameters
obj -- pointer to a chart object
cnt -- new number of points on the data lines
-
void
lv_chart_set_range(lv_obj_t *obj, lv_chart_axis_t axis, lv_coord_t min, lv_coord_t max)¶ Set the minimal and maximal y values on an axis
- Parameters
obj -- pointer to a chart object
axis --
LV_CHART_AXIS_PRIMARY_YorLV_CHART_AXIS_SECONDARY_Ymin -- minimum value of the y axis
max -- maximum value of the y axis
-
void
lv_chart_set_update_mode(lv_obj_t *obj, lv_chart_update_mode_t update_mode)¶ Set update mode of the chart object. Affects
- Parameters
obj -- pointer to a chart object
mode -- the update mode
-
void
lv_chart_set_div_line_count(lv_obj_t *obj, uint8_t hdiv, uint8_t vdiv)¶ Set the number of horizontal and vertical division lines
- Parameters
obj -- pointer to a chart object
hdiv -- number of horizontal division lines
vdiv -- number of vertical division lines
-
void
lv_chart_set_zoom_x(lv_obj_t *obj, uint16_t zoom_x)¶ Zoom into the chart in X direction
- Parameters
obj -- pointer to a chart object
zoom_x -- zoom in x direction. LV_ZOOM_NONE or 256 for no zoom, 512 double zoom
-
void
lv_chart_set_zoom_y(lv_obj_t *obj, uint16_t zoom_y)¶ Zoom into the chart in Y direction
- Parameters
obj -- pointer to a chart object
zoom_y -- zoom in y direction. LV_ZOOM_NONE or 256 for no zoom, 512 double zoom
-
uint16_t
lv_chart_get_zoom_x(const lv_obj_t *obj)¶ Get X zoom of a chart
- Parameters
obj -- pointer to a chart object
- Returns
the X zoom value
-
uint16_t
lv_chart_get_zoom_y(const lv_obj_t *obj)¶ Get Y zoom of a chart
- Parameters
obj -- pointer to a chart object
- Returns
the Y zoom value
-
void
lv_chart_set_axis_tick(lv_obj_t *obj, lv_chart_axis_t axis, lv_coord_t major_len, lv_coord_t minor_len, lv_coord_t major_cnt, lv_coord_t minor_cnt, bool label_en, lv_coord_t draw_size)¶ Set the number of tick lines on an axis
- Parameters
obj -- pointer to a chart object
axis -- an axis which ticks count should be set
major_len -- length of major ticks
minor_len -- length of minor ticks
major_cnt -- number of major ticks on the axis
minor_cnt -- number of minor ticks between two major ticks
label_en -- true: enable label drawing on major ticks
draw_size -- extra size required to draw the tick and labels (start with 20 px and increase if the ticks/labels are clipped)
-
lv_chart_type_t
lv_chart_get_type(const lv_obj_t *obj)¶ Get the type of a chart
- Parameters
obj -- pointer to chart object
- Returns
type of the chart (from 'lv_chart_t' enum)
-
uint16_t
lv_chart_get_point_count(const lv_obj_t *obj)¶ Get the data point number per data line on chart
- Parameters
chart -- pointer to chart object
- Returns
point number on each data line
-
uint16_t
lv_chart_get_x_start_point(const lv_obj_t *obj, lv_chart_series_t *ser)¶ Get the current index of the x-axis start point in the data array
- Parameters
chart -- pointer to a chart object
ser -- pointer to a data series on 'chart'
- Returns
the index of the current x start point in the data array
-
void
lv_chart_get_point_pos_by_id(lv_obj_t *obj, lv_chart_series_t *ser, uint16_t id, lv_point_t *p_out)¶ Get the position of a point to the chart.
- Parameters
chart -- pointer to a chart object
ser -- pointer to series
id -- the index.
p_out -- store the result position here
-
void
lv_chart_refresh(lv_obj_t *obj)¶ Refresh a chart if its data line has changed
- Parameters
chart -- pointer to chart object
-
lv_chart_series_t *
lv_chart_add_series(lv_obj_t *obj, lv_color_t color, lv_chart_axis_t axis)¶ Allocate and add a data series to the chart
- Parameters
obj -- pointer to a chart object
color -- color of the data series
axis -- the y axis to which the series should be attached (LV_CHART_AXIS_PRIMARY_Y or LV_CHART_AXIS_SECONDARY_Y)
- Returns
pointer to the allocated data series
-
void
lv_chart_remove_series(lv_obj_t *obj, lv_chart_series_t *series)¶ Deallocate and remove a data series from a chart
- Parameters
chart -- pointer to a chart object
series -- pointer to a data series on 'chart'
-
void
lv_chart_hide_series(lv_obj_t *chart, lv_chart_series_t *series, bool hide)¶ Hide/Unhide a single series of a chart.
- Parameters
obj -- pointer to a chart object.
series -- pointer to a series object
hide -- true: hide the series
-
void
lv_chart_set_series_color(lv_obj_t *chart, lv_chart_series_t *series, lv_color_t color)¶ Change the color of a series
- Parameters
obj -- pointer to a chart object.
series -- pointer to a series object
color -- the new color of the series
-
void
lv_chart_set_x_start_point(lv_obj_t *obj, lv_chart_series_t *ser, uint16_t id)¶ Set the index of the x-axis start point in the data array. This point will be considers the first (left) point and the other points will be drawn after it.
- Parameters
obj -- pointer to a chart object
ser -- pointer to a data series on 'chart'
id -- the index of the x point in the data array
-
lv_chart_series_t *
lv_chart_get_series_next(const lv_obj_t *chart, const lv_chart_series_t *ser)¶ Get the next series.
- Parameters
chart -- pointer to a chart
ser -- the previous series or NULL to get the first
- Returns
the next series or NULL if there is no more.
-
lv_chart_cursor_t *
lv_chart_add_cursor(lv_obj_t *obj, lv_color_t color, lv_dir_t dir)¶ Add a cursor with a given color
- Parameters
obj -- pointer to chart object
color -- color of the cursor
dir -- direction of the cursor.
LV_DIR_RIGHT/LEFT/TOP/DOWN/HOR/VER/ALL. OR-ed values are possible
- Returns
pointer to the created cursor
-
void
lv_chart_set_cursor_pos(lv_obj_t *chart, lv_chart_cursor_t *cursor, lv_point_t *pos)¶ Set the coordinate of the cursor with respect to the paddings
- Parameters
obj -- pointer to a chart object
cursor -- pointer to the cursor
pos -- the new coordinate of cursor relative to the chart
-
void
lv_chart_set_cursor_point(lv_obj_t *chart, lv_chart_cursor_t *cursor, lv_chart_series_t *ser, uint16_t point_id)¶ Stick the cursor to a point
- Parameters
obj -- pointer to a chart object
cursor -- pointer to the cursor
ser -- pointer to a series
point_id -- the point's index or
LV_CHART_POINT_NONEto not assign to any points.
-
lv_point_t
lv_chart_get_cursor_point(lv_obj_t *chart, lv_chart_cursor_t *cursor)¶ Get the coordinate of the cursor with respect to the paddings
- Parameters
obj -- pointer to a chart object
cursor -- pointer to cursor
- Returns
coordinate of the cursor as lv_point_t
-
void
lv_chart_set_all_value(lv_obj_t *obj, lv_chart_series_t *ser, lv_coord_t value)¶ Initialize all data points of a series with a value
- Parameters
obj -- pointer to chart object
ser -- pointer to a data series on 'chart'
value -- the new value for all points.
LV_CHART_POINT_NONEcan be used to hide the points.
-
void
lv_chart_set_next_value(lv_obj_t *obj, lv_chart_series_t *ser, lv_coord_t value)¶ Set the next point's Y value according to the update mode policy.
- Parameters
obj -- pointer to chart object
ser -- pointer to a data series on 'chart'
value -- the new value of the next data
-
void
lv_chart_set_next_value2(lv_obj_t *obj, lv_chart_series_t *ser, lv_coord_t x_value, lv_coord_t y_value)¶ Set the next point's X and Y value according to the update mode policy.
- Parameters
obj -- pointer to chart object
ser -- pointer to a data series on 'chart'
x_value -- the new X value of the next data
y_value -- the new Y value of the next data
-
void
lv_chart_set_value_by_id(lv_obj_t *obj, lv_chart_series_t *ser, uint16_t id, lv_coord_t value)¶ Set an individual point's y value of a chart's series directly based on its index
- Parameters
obj -- pointer to a chart object
ser -- pointer to a data series on 'chart'
id -- the index of the x point in the array
value -- value to assign to array point
-
void
lv_chart_set_value_by_id2(lv_obj_t *obj, lv_chart_series_t *ser, uint16_t id, lv_coord_t x_value, lv_coord_t y_value)¶ Set an individual point's x and y value of a chart's series directly based on its index Can be used only with
LV_CHART_TYPE_SCATTER.- Parameters
obj -- pointer to chart object
ser -- pointer to a data series on 'chart'
id -- the index of the x point in the array
x_value -- the new X value of the next data
y_value -- the new Y value of the next data
-
void
lv_chart_set_ext_y_array(lv_obj_t *obj, lv_chart_series_t *ser, lv_coord_t array[])¶ Set an external array for the y data points to use for the chart NOTE: It is the users responsibility to make sure the
point_cntmatches the external array size.- Parameters
obj -- pointer to a chart object
ser -- pointer to a data series on 'chart'
array -- external array of points for chart
-
void
lv_chart_set_ext_x_array(lv_obj_t *obj, lv_chart_series_t *ser, lv_coord_t array[])¶ Set an external array for the x data points to use for the chart NOTE: It is the users responsibility to make sure the
point_cntmatches the external array size.- Parameters
obj -- pointer to a chart object
ser -- pointer to a data series on 'chart'
array -- external array of points for chart
-
lv_coord_t *
lv_chart_get_y_array(const lv_obj_t *obj, lv_chart_series_t *ser)¶ Get the array of y values of a series
- Parameters
obj -- pointer to a chart object
ser -- pointer to a data series on 'chart'
- Returns
the array of values with 'point_count' elements
-
lv_coord_t *
lv_chart_get_x_array(const lv_obj_t *obj, lv_chart_series_t *ser)¶ Get the array of x values of a series
- Parameters
obj -- pointer to a chart object
ser -- pointer to a data series on 'chart'
- Returns
the array of values with 'point_count' elements
Variables
-
const lv_obj_class_t
lv_chart_class¶
-
struct
lv_chart_series_t¶ - #include <lv_chart.h>
Descriptor a chart series
-
struct
lv_chart_cursor_t¶
-
struct
lv_chart_tick_dsc_t¶
-
struct
lv_chart_t¶ Public Members
-
lv_ll_t
series_ll¶ Linked list for the series (stores lv_chart_series_t)
-
lv_ll_t
cursor_ll¶ Linked list for the cursors (stores lv_chart_cursor_t)
-
lv_chart_tick_dsc_t
tick[4]¶
-
lv_coord_t
ymin[2]¶
-
lv_coord_t
ymax[2]¶
-
lv_coord_t
xmin[2]¶
-
lv_coord_t
xmax[2]¶
-
lv_coord_t
pressed_point_id¶
-
uint16_t
hdiv_cnt¶ Number of horizontal division lines
-
uint16_t
vdiv_cnt¶ Number of vertical division lines
-
uint16_t
point_cnt¶ Point number in a data line
-
uint16_t
zoom_x¶
-
uint16_t
zoom_y¶
-
lv_chart_type_t
type¶ Line or column chart
-
lv_chart_update_mode_t
update_mode¶
-
lv_ll_t