Cocoa Open a fullscreen window on the second scree

问题:

I'm developing an app on OSX 10.7 and I'm trying and the goal is to open some images on a second screen while the app has to run normally on the first.

So the code is the following:

NSScreen *screen = [[NSScreen screens] objectAtIndex:1];

fullScreenWindow = [[NSWindow alloc] initWithContentRect:[screenFrame]
                                               styleMask:NSBorderlessWindowMask
                                                 backing:NSBackingStoreBuffered
                                                   defer:NO
                                                  screen:screen];
[fullScreenWindow setLevel: NSMainMenuWIndowLevel + 1];
[fullScreenWindow setOpaque: YES];
[fullScreenWindow setBackgroundColor:[NSColor yellowColor]];

fullScreenView = [[NSView alloc] initWithFrame:NSMakeRect(0.0f, 0.0f, fullScreenWindow.frame.size.width, fullScreenWindow.frame.size.height)];
// Adding a test button
NSButton *testButton = [[NSButton alloc] initWithFrame(50.0f, 50.0f, 100.0f, 50.0f)];
[testButton setTarget:self];
[testButton setAction:@selector(closeExternalWindow)];
[fullScreenView addSubview:testButton];

// Present the fullscreen window
[fullScreenWindow.contentView addSubview:fullScreenView];
[fullScreenWindow makeKeyAndOrderFront:self];

In this way, on the first screen the app is correctly shown, but on the second screen I just see a fullscreen black window.

What's the issue?

Thanks!

回答1:

Reading Apple's docs for initWithContentRect:styleMask:backing:defer:screen: it states that the screen parameter..

Specifies where the window’s content rectangle is drawn if the window is to be drawn in a screen other than the main screen. The content rectangle is drawn relative to the bottom-left corner of screen.

So when using [screen frame] you're actually moving it off the second screen as the positioning is relative to that screen already.

In order to make it appear where expected you can change the code e.g. to

[[NSWindow alloc] initWithContentRect:NSMakeRect(0, 0, [screen frame].size.width, [screen frame].size.height)
                            styleMask:NSBorderlessWindowMask
                              backing:NSBackingStoreBuffered
                                defer:NO
                               screen:screen];

回答2:

After some days I have had the possibility to work again on this code and now it works:

NSScreen *screen = [[NSScreen screens] objectAtIndex:1];
NSRect mainDisplayRect = [screen frame];
fullScreenWindow = [[NSWindow alloc] initWithContentRect: mainDisplayRect styleMask:NSBorderlessWindowMask
                                                 backing:NSBackingStoreBuffered defer:YES];
[fullScreenWindow setLevel:NSMainMenuWindowLevel+1];
[fullScreenWindow setOpaque:YES];
[fullScreenWindow setHidesOnDeactivate:YES];
[fullScreenWindow setBackgroundColor:[NSColor redColor]];

NSRect viewRect = NSMakeRect(0.0, 0.0, mainDisplayRect.size.width, mainDisplayRect.size.height);
fullScreenView = [[PresenterView alloc] initWithFrame:viewRect];
[fullScreenWindow setContentView: fullScreenView];
[fullScreenWindow makeKeyAndOrderFront:self];

Jay thank you for the support ;)