title: How to click through a window's transparent part in Cocoa and SFML
body: <p>I use <code>window.getSystemHandle()</code> in SFML and convert it to <code>NSWindow *</code>, the following code is used to make the window transparent:</p>
  <pre><code>NSWindow *cocoa_window = (NSWindow*)window.getSystemHandle() ;
  GLint opaque = 0;
  [cocoa_window setStyleMask:NSWindowStyleMaskBorderless];
  [cocoa_window setLevel: NSFloatingWindowLevel];
  [[[cocoa_window contentView] openGLContext] setValues:&amp;opaque forParameter:NSOpenGLContextParameterSurfaceOpacity];
  [cocoa_window setBackgroundColor:[NSColor clearColor]];
  [cocoa_window setOpaque:NO];
  </code></pre>
  <p>And I clean the window by:</p>
  <pre><code> window.clear(sf::Color::Transparent);
  </code></pre>
  <p>However, I can't <strong>click through</strong> the transparent part ( I want to receive mouse events when the user click on the opaque part) of the window. What can I do?</p>
  <p>Should I replace the line <code>[[[cocoa_window contentView] openGLContext] ...;</code> with something else? Or do something on SFML part instead?</p>