hello_widget.c

@@ -82,9 +82,20 @@ RectangularButton(g_sPushReset, &g_sPushBtn, 0, 0,
                    ClrDarkRed, ClrRed, ClrWhite, ClrWhite,
                    g_psFontCmss22b, "RESET", 0, 0, 0, 0, OnButtonReset);
 
+//*****************************************************************************
+//*****************************************************************************
+//
+// A global we use to keep track of whether or not the "Hello" widget is
+// currently visible.
+//
+//*****************************************************************************
 bool g_bHelloVisible = false;
 
-
+//*****************************************************************************
+//
+// The error routine that is called if the driver library encounters an error.
+//
+//*****************************************************************************
 #ifdef DEBUG
 void
 __error__(char *pcFilename, uint32_t ui32Line)
@@ -92,6 +103,27 @@ __error__(char *pcFilename, uint32_t ui32Line)
 }
 #endif
 
+//*****************************************************************************
+//
+// This function is called by the graphics library widget manager in the
+// context of WidgetMessageQueueProcess whenever the user releases the
+// "Press Me!" button.  We use this notification to display or hide the
+// "Hello!" widget.
+//
+// This is actually a rather inefficient way to accomplish this but it's
+// a good example of how to add and remove widgets dynamically.  In
+// normal circumstances, you would likely leave the g_sHello widget
+// linked into the tree and merely add or remove the text by changing
+// its style then repainting.
+//
+// If using this dynamic add/remove strategy, another useful optimization
+// is to use a black canvas widget that covers the same area of the screen
+// as the widgets that you will be adding and removing.  If this is the used
+// as the point in the tree where the subtree is added or removed, you can
+// repaint just the desired area by repainting the black canvas rather than
+// repainting the whole tree.
+//
+//*****************************************************************************
 void OnButtonPress(tWidget *psWidget)   // funkcja obslugujaca przycisk start
 {
     g_bHelloVisible = !g_bHelloVisible;