gfx/thebes/gfxQuartzNativeDrawing.h

   1 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  * This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef _GFXQUARTZNATIVEDRAWING_H_
   7 #define _GFXQUARTZNATIVEDRAWING_H_
   8
   9 #include "mozilla/Attributes.h"
  10
  11 #include "gfxContext.h"
  12 #include "gfxQuartzSurface.h"
  13 #include "mozilla/gfx/BorrowedContext.h"
  14 #include "nsAutoPtr.h"
  15
  16 class gfxQuartzNativeDrawing {
  17 public:
  18
  19     /* Create native Quartz drawing for a rectangle bounded by
  20      * nativeRect.
  21      *
  22      * Typical usage looks like:
  23      *
  24      *   gfxQuartzNativeDrawing nativeDraw(ctx, nativeRect);
  25      *   CGContextRef cgContext = nativeDraw.BeginNativeDrawing();
  26      *   if (!cgContext)
  27      *     return NS_ERROR_FAILURE;
  28      *
  29      *     ... call Quartz operations on CGContextRef to draw to nativeRect ...
  30      *
  31      *   nativeDraw.EndNativeDrawing();
  32      *
  33      * aNativeRect is the size of the surface (in Quartz/Cocoa points) that
  34      * will be created _if_ the gfxQuartzNativeDrawing decides to create a new
  35      * surface and CGContext for its drawing operations, which it then
  36      * composites into the target gfxContext.
  37      *
  38      * (Note that aNativeRect will be ignored if the gfxQuartzNativeDrawing
  39      * uses the target gfxContext directly.)
  40      *
  41      * The optional aBackingScale parameter is a scaling factor that will be
  42      * applied when creating and rendering into such a temporary surface.
  43      */
  44     gfxQuartzNativeDrawing(gfxContext *ctx,
  45                            const gfxRect& aNativeRect);
  46
  47     /* Returns a CGContextRef which may be used for native drawing.  This
  48      * CGContextRef is valid until EndNativeDrawing is called; if it is used
  49      * for drawing after that time, the result is undefined. */
  50     CGContextRef BeginNativeDrawing();
  51
  52     /* Marks the end of native drawing */
  53     void EndNativeDrawing();
  54
  55 private:
  56     // don't allow copying via construction or assignment
  57     gfxQuartzNativeDrawing(const gfxQuartzNativeDrawing&) MOZ_DELETE;
  58     const gfxQuartzNativeDrawing& operator=(const gfxQuartzNativeDrawing&) MOZ_DELETE;
  59
  60     // Final destination context
  61     nsRefPtr<gfxContext> mContext;
  62     mozilla::RefPtr<mozilla::gfx::DrawTarget> mDrawTarget;
  63     mozilla::gfx::BorrowedCGContext mBorrowedContext;
  64     mozilla::gfx::Rect mNativeRect;
  65
  66     // saved state
  67     CGContextRef mCGContext;
  68 };
  69
  70 #endif