diff options
Diffstat (limited to 'include/cru/ui/render/RenderObject.h')
-rw-r--r-- | include/cru/ui/render/RenderObject.h | 59 |
1 files changed, 31 insertions, 28 deletions
diff --git a/include/cru/ui/render/RenderObject.h b/include/cru/ui/render/RenderObject.h index cfa72b7d..bef2859e 100644 --- a/include/cru/ui/render/RenderObject.h +++ b/include/cru/ui/render/RenderObject.h @@ -5,34 +5,36 @@ #include "cru/common/String.h" namespace cru::ui::render { -// Render object will not destroy its children when destroyed. Control must -// manage lifecycle of its render objects. Since control will destroy its -// children when destroyed, render objects will be destroyed along with it. -// -// About layout: -// Render object should be able to deal with arbitrary size as the result of -// measure and layout. -// -// Parent may pass calculated preferred size down. But the preferred size set on -// child itself takes precedence. -// -// Each render object should obey the measure requirement to set size and report -// a warning when that requirement can't be satisfied with probably bigger size -// of children than that of itself and optional visual effect to indicate that. -// -// If size of chilren are less than min size requirement, then render object -// should try to fill the rest area. If size of children are more than max size -// requirement, then render object should display a warning of the layout -// problem and use the max size of itself with children exceeding its bound. -// (Or better you could use some visual effect to indicate that.) -// -// To write a custom RenderObject, override following methods: -// public: -// void Draw(platform::graphics::IPainter* painter) override; -// RenderObject* HitTest(const Point& point) override; -// protected: -// Size OnMeasureContent(const MeasureRequirement& requirement) override; -// void OnLayoutContent(const Rect& content_rect) override; +/** + * ### Layout + * + * Render object should be able to deal with _arbitrary_ size as the result of + * measure and layout. + * + * Parent may pass calculated preferred size down. But the preferred size set on + * child itself takes precedence. + * + * Each render object should obey the measure requirement to set size and report + * a warning when that requirement can't be satisfied with probably bigger size + * of children than that of itself and optional visual effect to indicate that. + * + * If size of chilren are less than min size requirement, then render object + * should try to fill the rest area. If size of children are more than max size + * requirement, then render object should display a warning of the layout + * problem and use the max size of itself with children exceeding its bound. + * (Or better you could use some visual effect to indicate that.) + * + * ### Create New Render Object + * + * To write a custom RenderObject, override following methods: + * + * public: + * void Draw(platform::graphics::IPainter* painter) override; + * RenderObject* HitTest(const Point& point) override; + * protected: + * Size OnMeasureContent(const MeasureRequirement& requirement) override; + * void OnLayoutContent(const Rect& content_rect) override; + */ class CRU_UI_API RenderObject : public Object { CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::render::RenderObject") @@ -137,6 +139,7 @@ class CRU_UI_API RenderObject : public Object { virtual void OnAttachedControlChanged(controls::Control* old_control, controls::Control* new_control) {} + virtual void OnResize(const Size& new_size) {} private: |