| // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #import <Cocoa/Cocoa.h> |
| |
| // CustomFrameView is a class whose methods we swizzle into NSGrayFrame |
| // on 10.7 and below, or NSThemeFrame on 10.8 and above, so that we can |
| // support custom frame drawing. This is used with a textured window so that |
| // AppKit does not draw a title bar. |
| // This class is never to be instantiated on its own. |
| // We explored a variety of ways to support custom frame drawing and custom |
| // window widgets. |
| // Our requirements were: |
| // a) that we could fall back on standard system drawing at any time for the |
| // "default theme" |
| // b) We needed to be able to draw both a background pattern, and an overlay |
| // graphic, and we need to be able to set the pattern phase of our background |
| // window. |
| // c) We had to be able to support "transparent" themes, so that you could see |
| // through to the underlying windows in places without the system theme |
| // getting in the way. |
| // |
| // Since we want "A" we couldn't just do a transparent borderless window. At |
| // least I couldn't find the right combination of HITheme calls to make it draw |
| // nicely, and I don't trust that the HITheme calls are going to exist in future |
| // system versions. |
| // "C" precluded us from inserting a view between the system frame and the |
| // the content frame in Z order. To get the transparency we actually need to |
| // replace the drawing of the system frame. |
| // "B" precluded us from just setting a background color on the window. |
| // |
| // Originally we tried overriding the private API +frameViewForStyleMask: to |
| // add our own subclass of NSGrayView to our window. Turns out that if you |
| // subclass NSGrayView it does not draw correctly when you call NSGrayView's |
| // drawRect. It appears that NSGrayView's drawRect: method (and that of its |
| // superclasses) do lots of "isMemberOfClass/isKindOfClass" calls, and if your |
| // class is NOT an instance of NSGrayView (as opposed to a subclass of |
| // NSGrayView) then the system drawing will not work correctly. |
| // |
| // Given all of the above, we found swizzling drawRect in _load to be the |
| // easiest and safest method of achieving our goals. We do the best we can to |
| // check that everything is safe, and attempt to fallback gracefully if it is |
| // not. |
| |
| @interface NSWindow (CustomFrameView) |
| |
| // To define custom window drawing behaviour, override this method on an |
| // NSWindow subclass. Call the default method (on super) to draw the |
| // default frame. |
| // NOTE: Always call the default implementation (even if you just immediately |
| // draw over it), otherwise the top-left and top-right corners of the window |
| // won't be drawn correctly. |
| - (void)drawCustomFrameRect:(NSRect)rect forView:(NSView*)view; |
| |
| @end |
