30 lines
963 B
Plaintext
30 lines
963 B
Plaintext
class Sized: MeasureResult {}
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class BaseRect: RectBlock {
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function measure(self: BaseRect, mount: Mount, constraints: Constraints): MeasureResult {
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return RectBlock.measure(self, mount, constraints)
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}
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}
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class WideRect: BaseRect {
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function measure(self: WideRect, mount: Object, constraints: Object): Sized {
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measured = BaseRect.measure(self, mount, constraints)
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return Sized(measured.width, measured.height)
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}
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}
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class Actions {
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rect: WideRect
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count: Object
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function widen(self: Actions): Unit {
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self.rect.width = 260
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self.count.increment()
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}
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}
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rect = WideRect(180, 60, 8, "#ED6A5A")
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count = ui.state(0)
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actions = Actions(rect, count)
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button = Button("扩大矩形")
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button.onClick(actions.widen)
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root = Column(24, 16, TextBlock("参数可以更宽，返回类型可以更具体", 2), rect, button, ui.textOf(count, "value"))
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page = Page()
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page.title = "方法覆写契约"
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page.render(root)
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