Windows

Dynamic positioning windows

• Demonstration
• Functionality:
  • Create an application with 2 windows:
    • The main window:
      • it has a caption (title) bar
      • it is resizable (including minimizing and maximizing) with a standard border
      • the background colour of the client area is standard
      • it is placed above all non-topmost windows
      • it is visible on the taskbar and in the alt-tab switching window
      • closing it, ends the application
    • The transparent window:
      • it has no caption (title) bar
      • it has no border
      • the colour of the window is the same as a colour defined in the system for the caption bar for active windows
      • it is semitransparent (with the alpha parameter set to 50%)
      • it is placed above all non-topmost windows
      • it is invisible on the taskbar and in the window of the alt-tab switching
      • size and position:
        • if there is no foreground window or the foreground window is the main or the transparent window of this aplication, the transparent window takes a quarter of the screen
        • in other cases, it takes a quarter of the foreground window
        • the taken quarter depends on the position of the centre point of the main window - if it is placed in the left-top quarter of the screen, the transparent window takes the left-top quarter (of the screen or the foreground window), and analogously for other quarters
        • changing positioning of the transparent window can be delayed (as in the demonstration)
      • it is impossible to place it above the main window in any way
• Assumptions (for simplicity):
  • there is only one screen
  • the size of the screen does not change during running the application
• Hints:
  • GetSystemMetrics, SM_CXSCREEN, SM_CYSCREEN
  • WS_EX_LAYERED, SetLayeredWindowAttributes()
  • SetTimer(), WM_TIMER
  • GetForegroundWindow()
  • GetWindowRect()
  • MoveWindow(), SetWindowPos(), BringWindowToTop()
• Approximate points:
  • Features of the main window: 2.0
  • Features of the transparent window:
    • no caption and no border: 1.0
    • colour and semitransparency: 1.0
    • size and position: 5.0
    • other features: 1.0

• Links for uploading:
  • Solutions
  • Corrections