Clip drawing in wxRendererGeneric::DrawHeaderButtonContents().

Clip drawing of the icon and bitmap to the header rectangle.

Don't clip the text because we already ellipsize it to avoid overflowing but
do the ellipsization correctly, using wxControl::Ellipsize() instead of the
simple (and wrong) duplicated version here.

Also correct and simplify the alignment calculations.

Closes #12047.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@64309 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/renderg.cpp

@@ -328,51 +328,57 @@ wxRendererGeneric::DrawHeaderButtonContents(wxWindow *win,
         wxDCPenChanger setPen(dc, c);
         wxDCBrushChanger setBrush(dc, c);
 
+        wxDCClipper clip(dc, rect);
         dc.DrawPolygon( 3, triPt, ar.x, ar.y);
     }
     labelWidth += arrowSpace;
 
-    const int margin = 5;   // number of pixels to reserve on either side of the label
     int bmpWidth = 0;
 
-    if ( params && params->m_labelBitmap.Ok() )
-        bmpWidth = params->m_labelBitmap.GetWidth() + 2;
-
-    labelWidth += bmpWidth + 2*margin;
-
     // draw the bitmap if there is one
     if ( params && params->m_labelBitmap.Ok() )
     {
-        int w, h, x, y;
+        int w = params->m_labelBitmap.GetWidth();
-        w = params->m_labelBitmap.GetWidth();
+        int h = params->m_labelBitmap.GetHeight();
-        h = params->m_labelBitmap.GetHeight();
 
-        x = margin + rect.x;
+        const int margin = 1; // an extra pixel on either side of the bitmap
-        y = rect.y + wxMax(1, (rect.height - h) / 2);
 
-        if (params->m_labelText.empty())
+        bmpWidth = w + 2*margin;
+        labelWidth += bmpWidth;
+
+        int x = rect.x + margin;
+        const int y = rect.y + wxMax(1, (rect.height - h) / 2);
+
+        const int extraSpace = rect.width - labelWidth;
+        if ( params->m_labelText.empty() && extraSpace > 0 )
         {
             // use the alignment flags
             switch (params->m_labelAlignment)
             {
                 default:
                 case wxALIGN_LEFT:
-                    x = rect.x + margin;
                     break;
+
                 case wxALIGN_CENTER:
-                    x = rect.x + wxMax(1, (rect.width - arrowSpace - w)/2);
+                    x += extraSpace/2;
                     break;
+
                 case wxALIGN_RIGHT:
-                    x = rect.x + wxMax(1, rect.width - arrowSpace - margin - w);
+                    x += extraSpace;
                     break;
             }
         }
+
+        wxDCClipper clip(dc, rect);
         dc.DrawBitmap(params->m_labelBitmap, x, y, true);
     }
 
     // Draw a label if one is given
     if ( params && !params->m_labelText.empty() )
     {
+        const int margin = 5;   // number of pixels to reserve on either side of the label
+        labelWidth += 2*margin;
+
         wxFont font  = params->m_labelFont.Ok() ?
             params->m_labelFont : win->GetFont();
         wxColour clr = params->m_labelColour.Ok() ?
@@ -384,41 +390,46 @@ wxRendererGeneric::DrawHeaderButtonContents(wxWindow *win,
         dc.SetTextForeground(clr);
         dc.SetBackgroundMode(wxBRUSHSTYLE_TRANSPARENT);
 
-        int tw, th, td, x, y;
+        int tw, th, td;
         dc.GetTextExtent( label, &tw, &th, &td);
-        labelWidth += tw;
+
-        y = rect.y + wxMax(0, (rect.height - (th+td)) / 2);
+        int x = rect.x + bmpWidth + margin;
+        const int y = rect.y + wxMax(0, (rect.height - (th+td)) / 2);
 
         // truncate and add an ellipsis (...) if the text is too wide.
-        int targetWidth = rect.width - arrowSpace - bmpWidth - 2*margin;
+        const int availWidth = rect.width - labelWidth;
-        if ( tw > targetWidth )
+        if ( tw > availWidth )
         {
-            int ellipsisWidth;
+            label = wxControl::Ellipsize(label,
-            dc.GetTextExtent( wxT("..."), &ellipsisWidth, NULL);
+                                         dc,
-            do {
+                                         wxELLIPSIZE_END,
-                label.Truncate( label.length() - 1 );
+                                         availWidth,
-                dc.GetTextExtent( label, &tw, &th);
+                                         wxELLIPSIZE_FLAGS_NONE);
-            } while (tw + ellipsisWidth > targetWidth && label.length() );
+            tw = dc.GetTextExtent(label).x;
-            label.append( wxT("...") );
+        }
-            tw += ellipsisWidth;
+        else // enough space, we can respect alignment
+        {
+            switch (params->m_labelAlignment)
+            {
+                default:
+                case wxALIGN_LEFT:
+                    break;
+
+                case wxALIGN_CENTER:
+                    x += (availWidth - tw)/2;
+                    break;
+
+                case wxALIGN_RIGHT:
+                    x += availWidth - tw;
+                    break;
+            }
         }
 
-        switch (params->m_labelAlignment)
+        dc.DrawText(label, x, y);
-        {
-            default:
-            case wxALIGN_LEFT:
-                x = rect.x + margin;
-                break;
-            case wxALIGN_CENTER:
-                x = rect.x + wxMax(0, (rect.width - arrowSpace  - tw - bmpWidth)/2);
-                break;
-            case wxALIGN_RIGHT:
-                x = rect.x + wxMax(0, rect.width - arrowSpace - margin - tw - bmpWidth);
-                break;
-        }
 
-        dc.DrawText(label, x + bmpWidth, y);
+        labelWidth += tw;
     }
+
     return labelWidth;
 }