added wxBG_STYLE_TRANSPARENT and implemented it for wxMac; documented various transparency-related functions

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@49341 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/shaped/shaped.cpp

@@ -58,12 +58,13 @@ public:
 };
 
 
-// Define a new frame type: this is going to be our main frame
+// Define a new frame type: this is going to the frame showing the
+// effect of wxFRAME_SHAPED
 class ShapedFrame : public wxFrame
 {
 public:
     // ctor(s)
-    ShapedFrame();
+    ShapedFrame(wxFrame *parent);
     void SetWindowShape();
 
     // event handlers (these functions should _not_ be virtual)
@@ -84,6 +85,35 @@ private:
     DECLARE_EVENT_TABLE()
 };
 
+// Define a new frame type: this is going to the frame showing the
+// effect of wxWindow::SetTransparent and of
+// wxWindow::SetBackgroundStyle(wxBG_STYLE_TRANSPARENT)
+class SeeThroughFrame : public wxFrame
+{
+public:
+    // ctor(s)
+    SeeThroughFrame();
+
+    // event handlers (these functions should _not_ be virtual)
+    void OnDoubleClick(wxMouseEvent& evt);
+    void OnPaint(wxPaintEvent& evt);
+    void OnSize(wxSizeEvent& evt);
+
+private:
+    enum State
+    {
+        STATE_SEETHROUGH,
+        STATE_TRANSPARENT,
+        STATE_OPAQUE,
+        STATE_MAX
+    };
+
+    State m_currentState;
+
+    // any class wishing to process wxWidgets events must use this macro
+    DECLARE_EVENT_TABLE()
+};
+
 
 // ----------------------------------------------------------------------------
 // event tables and other macros for wxWidgets
@@ -130,10 +160,14 @@ bool MyApp::OnInit()
 
     wxInitAllImageHandlers();
 
-    // Create the main application window
-    ShapedFrame *frame = new ShapedFrame();
-    frame->Show(true);
-    SetTopWindow(frame);
+    // Create the transparent window
+    SeeThroughFrame *seeThroughFrame = new SeeThroughFrame();
+    seeThroughFrame->Show(true);
+    SetTopWindow(seeThroughFrame);
+
+    // Create the shaped window
+    ShapedFrame *shapedFrame = new ShapedFrame(seeThroughFrame);
+    shapedFrame->Show(true);
 
     // success: wxApp::OnRun() will be called which will enter the main message
     // loop and the application will run. If we returned false here, the
@@ -142,12 +176,12 @@ bool MyApp::OnInit()
 }
 
 // ----------------------------------------------------------------------------
-// main frame
+// shaped frame
 // ----------------------------------------------------------------------------
 
 // frame constructor
-ShapedFrame::ShapedFrame()
-       : wxFrame((wxFrame *)NULL, wxID_ANY, wxEmptyString,
+ShapedFrame::ShapedFrame(wxFrame *parent)
+       : wxFrame(parent, wxID_ANY, wxEmptyString,
                   wxDefaultPosition, wxSize(100, 100), //wxDefaultSize,
                   0
                   | wxFRAME_SHAPED
@@ -235,3 +269,93 @@ void ShapedFrame::OnWindowCreate(wxWindowCreateEvent& WXUNUSED(evt))
     SetWindowShape();
 }
 
+// ----------------------------------------------------------------------------
+// see-through frame
+// ----------------------------------------------------------------------------
+
+// frame constructor
+SeeThroughFrame::SeeThroughFrame()
+       : wxFrame(NULL, wxID_ANY, "Transparency test: double click here",
+                  wxPoint(100, 30), wxSize(300, 300),
+                  wxDEFAULT_FRAME_STYLE | wxSTAY_ON_TOP),
+         m_currentState(STATE_SEETHROUGH)
+{
+    SetBackgroundColour(wxColour(255, 255, 255, 255));
+    SetBackgroundStyle(wxBG_STYLE_TRANSPARENT);
+}
+
+// Redraws the whole window on resize
+void SeeThroughFrame::OnSize(wxSizeEvent& WXUNUSED(evt))
+{
+    Refresh();
+}
+
+// Paints a grid of varying hue and alpha
+void SeeThroughFrame::OnPaint(wxPaintEvent& WXUNUSED(evt))
+{
+    wxPaintDC dc(this);
+    dc.SetPen(wxNullPen);
+
+    int xcount = 8;
+    int ycount = 8;
+
+    float xstep = 1. / xcount;
+    float ystep = 1. / ycount;
+
+    int width = GetClientSize().GetWidth();
+    int height = GetClientSize().GetHeight();
+
+    for ( float x = 0.; x < 1.; x += xstep )
+    {
+        for ( float y = 0.; y < 1.; y += ystep )
+        {
+            wxImage::RGBValue v = wxImage::HSVtoRGB(wxImage::HSVValue(x, 1., 1.));
+            dc.SetBrush(wxBrush(wxColour(v.red, v.green, v.blue,
+                                (int)(255*(1. - y)))));
+            int x1 = (int)(x * width);
+            int y1 = (int)(y * height);
+            int x2 = (int)((x + xstep) * width);
+            int y2 = (int)((y + ystep) * height);
+            dc.DrawRectangle(x1, y1, x2 - x1, y2 - y1);
+        }
+    }
+}
+
+// Switches between colour and transparent background on doubleclick
+void SeeThroughFrame::OnDoubleClick(wxMouseEvent& WXUNUSED(evt))
+{
+    m_currentState = (State)((m_currentState + 1) % STATE_MAX);
+
+    switch ( m_currentState )
+    {
+        case STATE_OPAQUE:
+            SetBackgroundStyle(wxBG_STYLE_COLOUR);
+            SetTransparent(255);
+            SetTitle("Opaque");
+            break;
+
+        case STATE_SEETHROUGH:
+            SetBackgroundStyle(wxBG_STYLE_TRANSPARENT);
+            SetTransparent(255);
+            SetTitle("See through");
+            break;
+
+        case STATE_TRANSPARENT:
+            SetBackgroundStyle(wxBG_STYLE_COLOUR);
+            SetTransparent(128);
+            SetTitle("Semi-transparent");
+            break;
+
+        case STATE_MAX:
+            wxFAIL_MSG( "unreachable" );
+    }
+
+    Refresh();
+}
+
+BEGIN_EVENT_TABLE(SeeThroughFrame, wxFrame)
+    EVT_LEFT_DCLICK(SeeThroughFrame::OnDoubleClick)
+    EVT_PAINT(SeeThroughFrame::OnPaint)
+    EVT_SIZE(SeeThroughFrame::OnSize)
+END_EVENT_TABLE()
+