nanogui-experiments/nanogui_customwidget.py

#!/usr/bin/env python3

import nanogui
from nanogui import glfw
from nanogui import BoxLayout, Color, Label, Orientation, Screen, Widget, Window, Vector2i
from nanogui.nanovg import LerpRGBA, RGBAf, RGB


class CustomWidget(Widget):
    def __init__(self, parent, size=(100, 100), color=Color(192, 0, 0, 255)):
        super().__init__(parent)
        self._size = size
        self.color = RGBAf(color.r, color.g, color.b, color.w)

    def preferred_size(self, ctx):
        return Vector2i(self._size)

    def draw(self, ctx):
        pos = self.position()
        size = self.size()

        ctx.BeginPath()
        ctx.Rect(pos[0], pos[1], size[0], size[1])
        bg = LerpRGBA(RGB(64, 64, 64), self.color, 0.3)
        ctx.FillColor(bg)
        ctx.Fill()
        ctx.BeginPath()
        ctx.StrokeWidth(5.0)
        ctx.StrokeColor(self.color)
        ctx.Rect(
            pos[0] + size[0] / 4.0,
            pos[1] + size[1] / 4.0,
            size[0] / 2.0,
            size[1] / 2.0,
        )
        ctx.Stroke()
        ctx.ClosePath()


class CustomWidgetApp(Screen):
    def __init__(self, size=(400, 300)):
        super().__init__(size, "NanoGUI CustomWidget")
        self.win = Window(self, "Demo Window")

        self.win.set_layout(BoxLayout(Orientation.Vertical, margin=20, spacing=20))
        self.resize_event(size)

        Label(self.win, "NanoGUI CustomWidget Demo", "sans-bold")

        _ = CustomWidget(self.win, (200, 100))

        self.draw_all()
        self.set_visible(True)
        self.perform_layout()

    def resize_event(self, size):
        self.win.set_fixed_size(size)
        self.win.set_size(size)
        self.win.center()
        self.win.perform_layout(self.nvg_context())
        super().resize_event(size)
        return True

    def keyboard_event(self, key, scancode, action, modifiers):
        if super().keyboard_event(key, scancode, action, modifiers):
            return True

        if key == glfw.KEY_ESCAPE and action == glfw.PRESS:
            self.set_visible(False)
            return True

        return False


if __name__ == "__main__":
    import gc

    nanogui.init()
    app = CustomWidgetApp()
    nanogui.mainloop(refresh=1 / 60.0 * 1000)
    del app
    gc.collect()
    nanogui.shutdown()