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Charts overview

#include <toolkit/charts/chart_interaction.hpp> (shared by every chart widget below)

All chart widgets (LineChart, BarChart, StackedBarChart, AreaChart, PieChart, ScatterPlot, Histogram, CandlestickChart) are Widget subclasses that own their own data (via add_series()/set_slices() etc.) and render axes, grid, legend, and hover tooltips themselves — there is no separate "chart view + model" split like the item/tree/table views use.

Common shape​

Most chart classes share the same small vocabulary:

MemberDescription
add_series(Series) / clear_series() / series_count()Add and manage data series (PieChart uses set_slices()/clear() instead)
set_title(std::string)Chart title
set_x_label(std::string) / set_y_label(std::string)Axis labels
set_show_grid(bool) / set_show_legend(bool)Toggle chrome
on_hover — std::function<void(size_t series_idx, size_t point_idx)>Fired as the pointer moves over a data point/bar/candle

Each series struct carries its own Color (or line_color/fill_color, or up_color/down_color for candlesticks), so per-series styling is set at data-population time rather than through separate style setters.

Pan & zoom — ChartInteraction​

Line, bar, stacked-bar, area, scatter, histogram, and candlestick charts embed a ChartInteraction to support scroll-to-zoom and drag-to-pan over the data range; PieChart does not use it. It's driven internally by each chart's handle_mouse() — you generally don't touch it directly, but it's useful to know it exists if you're debugging pan/zoom behavior or extending a chart:

struct ChartInteraction {
    void set_data_range(float dx_min, float dx_max, float dy_min, float dy_max);
    bool handle_scroll(float mx, float my, float scroll_dy, bool shift_held,
                       float plot_x, float plot_w, float plot_y, float plot_h);
    bool handle_press(float mx, float my);
    bool handle_drag(float mx, float my, float plot_x, float plot_w, float plot_y, float plot_h);
    bool handle_release();
    void reset_zoom();
    bool is_zoomed() const;
};

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