Create a Window::Layer interface to reduce sk_app glue code

This also makes it possible to manage other parts of viewer, etc (like
the stats screen, command set, even samples) as additional layers in the
stack. For now, it just removes a lot of boilerplate.

Bug: skia:
Change-Id: Ic2f80690fc76c683b3736287dc2b738c50d38614
Reviewed-on: https://skia-review.googlesource.com/82688
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

1 files changed, 10 insertions, 8 deletions

diff --git a/tools/viewer/Viewer.h b/tools/viewer/Viewer.h
index ff47b35f7f..1f5d1c5dc4 100644
--- a/tools/viewer/Viewer.h
+++ b/tools/viewer/Viewer.h
@@ -20,19 +20,21 @@
 
 class SkCanvas;
 
-class Viewer : public sk_app::Application {
+class Viewer : public sk_app::Application, sk_app::Window::Layer {
 public:
     Viewer(int argc, char** argv, void* platformData);
     ~Viewer() override;
 
-    void onBackendCreated();
-    void onPaint(SkCanvas* canvas);
     void onIdle() override;
-    bool onTouch(intptr_t owner, sk_app::Window::InputState state, float x, float y);
-    bool onMouse(float x, float y, sk_app::Window::InputState state, uint32_t modifiers);
-    void onUIStateChanged(const SkString& stateName, const SkString& stateValue);
-    bool onKey(sk_app::Window::Key key, sk_app::Window::InputState state, uint32_t modifiers);
-    bool onChar(SkUnichar c, uint32_t modifiers);
+
+    void onBackendCreated() override;
+    void onPaint(SkCanvas* canvas) override;
+    bool onTouch(intptr_t owner, sk_app::Window::InputState state, float x, float y) override;
+    bool onMouse(int x, int y, sk_app::Window::InputState state, uint32_t modifiers) override;
+    bool onMouseWheel(float delta, uint32_t modifiers) override;
+    void onUIStateChanged(const SkString& stateName, const SkString& stateValue) override;
+    bool onKey(sk_app::Window::Key key, sk_app::Window::InputState state, uint32_t modifiers) override;
+    bool onChar(SkUnichar c, uint32_t modifiers) override;
 
 private:
     enum class ColorMode {