every windows application is a citizen of Windows OS and the mouse is shared between them. If your applications shows some critical dialog to get response, but its quite possible that your dialog can be skipped by user and take another application window. How can you restrict the mouse cursor inside your application window?

For instance, the following application – CursorJail. How can you close your mouse pointer into the dialog prison?


You can use the api – ClipCursor(). See the following code snippet.

// Get window rect.
RECT WindowRect;
GetWindowRect( &WindowRect );

// Restrict the cursor
ClipCursor( &WindowRect );
...
// Free the cursor.
ClipCursor( 0 );

Well, need the code snippet for drawing prison? ;) 

// Get client rect.
CRect ClientRect;
GetClientRect( &ClientRect );

const int SteelBarCount = 5;
int xOffset = ClientRect.Width() / SteelBarCount;

dc.Draw3dRect( 0,0, ClientRect.Width(), ClientRect.Height(), 0, 0 );
// Draw steel bars.

for( int SteelBarIndex = 1; SteelBarIndex < SteelBarCount; ++SteelBarIndex )
{
    dc.MoveTo( xOffset * SteelBarIndex, 0 );
    dc.LineTo( xOffset * SteelBarIndex, ClientRect.Height());
}

dc.MoveTo( 0,0 );
dc.LineTo( ClientRect.Width(), ClientRect.Height());


You can use this clip feature to restrict the cursor between different dialogs of same application. You can hide a lot of GUI bugs. Try it ;)


Targeted Audience – Beginners.