initial commit

Signed-off-by: Peter Siegmund <mars3142@noreply.mars3142.dev>

libs/wxWidgets-3.3.1/interface/wx/overlay.h

@@ -0,0 +1,143 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        overlay.h
+// Purpose:     interface of wxOverlay
+// Author:      wxWidgets team
+// Licence:     wxWindows licence
+/////////////////////////////////////////////////////////////////////////////
+
+/**
+   @class wxOverlay
+
+   Creates an overlay over an existing window, allowing for manipulations like
+   rubber-banding, etc.
+
+   Overlay is implemented internally as a native window shown on top of the
+   window it is used with and it is more efficient to keep the wxOverlay object
+   around instead of recreating it every time it's needed, i.e. typically you
+   would have a member variable of type wxOverlay in your window class.
+
+   The overlay is initialized automatically when it is used by wxDCOverlay or
+   wxOverlayDC but has to be cleared manually, using its Reset() function, when
+   its contents shouldn't be shown any longer.
+
+   Use of this class is shown in the @ref page_samples_drawing where pressing
+   the left mouse button and dragging the mouse creates a rubber band effect
+   using wxOverlay.
+
+   @library{wxcore}
+
+   @see wxDCOverlay, wxOverlayDC
+ */
+class wxOverlay
+{
+public:
+    wxOverlay();
+    ~wxOverlay();
+
+    /**
+       Clears the overlay without restoring the former state.  To be done, for
+       example, when the window content has been changed and repainted.
+    */
+    void Reset();
+
+    /**
+        Sets or unsets constant opacity of the overlay window.
+
+        If @a alpha is `-1`, use per-pixel alpha blending, otherwise use the
+        given alpha value for all pixels.
+
+        @note Drawing on the overlay window is opaque by default under wxMSW.
+        You have to call SetOpacity(-1) before initializing the overlay and use
+        a graphics context to do the actual drawing if you want per-pixel alpha
+        blending. Or, assuming that SetOpacity(-1) wasn't called, explicitly set
+        the alpha value (at any time) to change the overlay window's opacity.
+
+        @note This is currently only implemented for wxMSW and does nothing in
+        the other ports.
+
+        @since 3.3.0
+    */
+    void SetOpacity(int alpha);
+};
+
+
+
+/**
+   @class wxDCOverlay
+
+   Connects an overlay with a drawing DC.
+
+   Note that when using wxDCOverlay with wxClientDC, which is the most common
+   case, using wxOverlayDC class is simpler and so is recommended.
+
+   @library{wxcore}
+
+   @see wxOverlay, wxDC, wxOverlayDC
+
+ */
+class wxDCOverlay
+{
+public:
+    /**
+       Connects this overlay to the corresponding drawing dc, if the overlay is
+       not initialized yet this call will do so.
+    */
+    wxDCOverlay(wxOverlay &overlay, wxDC *dc, int x , int y , int width , int height);
+
+    /**
+       Convenience wrapper that behaves the same using the entire area of the dc.
+    */
+    wxDCOverlay(wxOverlay &overlay, wxDC *dc);
+
+    /**
+       Removes the connection between the overlay and the dc.
+    */
+    virtual ~wxDCOverlay();
+
+    /**
+       Clears the layer, restoring the state at the last init.
+    */
+    void Clear();
+};
+
+/**
+   @class wxOverlayDC
+
+   A device context allowing to draw on an overlay associated with a window.
+
+   Assuming `MyWindow` as a wxWindow-derived object with `wxOverlay m_overlay`
+   as a member variable, this class could be used in the following way:
+
+   @code
+   void MyWindow::OnDrawSomethingTemporary()
+   {
+       wxOverlayDC dc(m_overlay, this);
+       dc.Clear(); // Usually required, unless the entire DC is filled.
+
+       // Use wxDC functions as usual.
+       dc.DrawText("Hello, world!", 10, 10);
+   }
+
+   void MyWindow::OnClearTemporaryDrawing()
+   {
+       m_overlay.Reset();
+   }
+   @endcode
+
+   Note that while wxOverlayDC currently actually inherits from wxClientDC,
+   this is an implementation detail and shouldn't be relied upon, it is only
+   guaranteed to derive from wxDC as documented here.
+
+   @library{wxcore}
+
+   @see wxOverlay, wxDCOverlay, wxDC
+
+   @since 3.3.0
+ */
+class wxOverlayDC : public wxDC
+{
+public:
+    wxOverlayDC(wxOverlay& overlay, wxWindow* win);
+
+    wxOverlayDC(wxOverlay& overlay, wxWindow* win, const wxRect& rect);
+};