Sep 1998 Tips & Tidbits

by Steve Sisak

Smarter ZoomWindows

Here's a painless substitute for ZoomWindow. I originally wrote the SmartZoomWindow wrapper to add multiple monitor support to ZoomWindow. Recently I tweaked the code to compensate for Mac OS 8 "fat borders" (actually it should work correctly with any WDEF geometry.)

I inset the zoom out by 3 pixels. I do this because some displays still have rounded corners that will crop the window's corners. Additionally I like to leave a small gap around the edge of a window so I can click into the Finder. If you desired to adjoin the window with the Menubar and display edges set kInsetZoomOut to zero.

Remember to compensate for "fat borders" in your window position and window staggering routines.

Public Interface
   enum {
      kInsetZoomOut = 3
   };

   void SmartZoomWindow(
         WindowPtr targetWindow,
         short partCode,
         Boolean bringFront);

Implementation
static void 
_LocalToGlobalRect(
   Rect *targetRect)
{
   LocalToGlobal((Point*)(&targetRect->top));
   LocalToGlobal((Point*)(&targetRect->bottom));
}

void SmartZoomWindow(
   WindowPtr targetWindow,
   short partCode,
   Boolean front)
{
   GrafPtr savePort;
   GDHandle dstGDevice;
   GDHandle testGDevice;
   Rect srcRect;
   Rect dstRect;
   Rect testRect;
   long dstArea;
   long testArea;
   short titleHeight;
   short borderWidth;

   if(targetWindow)
   {
      GetPort(&savePort);
      SetPort(targetWindow);

      if(partCode == inZoomOut)
      {
         srcRect = targetWindow->portRect;
         _LocalToGlobalRect(&srcRect);
         titleHeight = srcRect.top - 1 -
            (*((WindowPeek)targetWindow)->strucRgn)->rgnBBox.top;
         borderWidth = srcRect.left - 1 -
            (*((WindowPeek)targetWindow)->strucRgn)->rgnBBox.left;
         srcRect.top -= titleHeight;
         dstArea = 0;
         testGDevice = GetDeviceList();

         while(testGDevice)
         {
            if(TestDeviceAttribute(testGDevice, screenDevice))
            {
               if(TestDeviceAttribute(testGDevice, screenActive))
               {
                  SectRect(&srcRect, & (*testGDevice)->gdRect,
                                               &testRect);
                  testArea = (long)(testRect.right - testRect.left) *
                              (long)(testRect.bottom - testRect.top);
                  if(testArea > dstArea)
                  {
                     dstGDevice = testGDevice;
                     dstArea = testArea;
                  }
               }
            }

            testGDevice = GetNextDevice(testGDevice);
         }

         if(dstGDevice == GetMainDevice())
         {
            titleHeight += GetMBarHeight();
         }

         dstRect = (*dstGDevice)->gdRect;
         dstRect.top += titleHeight + kInsetZoomOut;
         dstRect.left += borderWidth + kInsetZoomOut;
         dstRect.right -= borderWidth + kInsetZoomOut;
         dstRect.bottom -= borderWidth + kInsetZoomOut;
         (*(WStateDataHandle)((WindowPeek)targetWindow)-
                            >dataHandle)->stdState = dstRect;
      }

      ZoomWindow(targetWindow, partCode, front);

      SetPort(savePort);
   }
}

Craig Marciniak
craig@marciniac.com