summaryrefslogtreecommitdiffstats
path: root/gfx/2d/BorrowedContext.h
blob: edb923b1ea1f396c7791ebb9ada11e38a8dd2afe (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef _MOZILLA_GFX_BORROWED_CONTEXT_H
#define _MOZILLA_GFX_BORROWED_CONTEXT_H

#include "2D.h"

#ifdef MOZ_X11
#include <X11/extensions/Xrender.h>
#include <X11/Xlib.h>
#include "X11UndefineNone.h"
#endif

struct _cairo;
typedef struct _cairo cairo_t;

namespace mozilla {

namespace gfx {

/* This is a helper class that let's you borrow a cairo_t from a
 * DrawTargetCairo. This is used for drawing themed widgets.
 *
 * Callers should check the cr member after constructing the object
 * to see if it succeeded. The DrawTarget should not be used while
 * the context is borrowed. */
class BorrowedCairoContext
{
public:
  BorrowedCairoContext()
    : mCairo(nullptr)
    , mDT(nullptr)
  { }

  explicit BorrowedCairoContext(DrawTarget *aDT)
    : mDT(aDT)
  {
    mCairo = BorrowCairoContextFromDrawTarget(aDT);
  }

  // We can optionally Init after construction in
  // case we don't know what the DT will be at construction
  // time.
  cairo_t *Init(DrawTarget *aDT)
  {
    MOZ_ASSERT(!mDT, "Can't initialize twice!");
    mDT = aDT;
    return mCairo = BorrowCairoContextFromDrawTarget(aDT);
  }

  // The caller needs to call Finish if cr is non-null when
  // they are done with the context. This is currently explicit
  // instead of happening implicitly in the destructor to make
  // what's happening in the caller more clear. It also
  // let's you resume using the DrawTarget in the same scope.
  void Finish()
  {
    if (mCairo) {
      ReturnCairoContextToDrawTarget(mDT, mCairo);
      mCairo = nullptr;
    }
  }

  ~BorrowedCairoContext() {
    MOZ_ASSERT(!mCairo);
  }

  cairo_t *mCairo;
private:
  static cairo_t* BorrowCairoContextFromDrawTarget(DrawTarget *aDT);
  static void ReturnCairoContextToDrawTarget(DrawTarget *aDT, cairo_t *aCairo);
  DrawTarget *mDT;
};

#ifdef MOZ_X11
/* This is a helper class that let's you borrow an Xlib drawable from
 * a DrawTarget. This is used for drawing themed widgets.
 *
 * Callers should check the Xlib drawable after constructing the object
 * to see if it succeeded. The DrawTarget should not be used while
 * the drawable is borrowed. */
class BorrowedXlibDrawable
{
public:
  BorrowedXlibDrawable()
    : mDT(nullptr),
      mDisplay(nullptr),
      mDrawable(X11None),
      mScreen(nullptr),
      mVisual(nullptr),
      mXRenderFormat(nullptr)
  {}

  explicit BorrowedXlibDrawable(DrawTarget *aDT)
    : mDT(nullptr),
      mDisplay(nullptr),
      mDrawable(X11None),
      mScreen(nullptr),
      mVisual(nullptr),
      mXRenderFormat(nullptr)
  {
    Init(aDT);
  }

  // We can optionally Init after construction in
  // case we don't know what the DT will be at construction
  // time.
  bool Init(DrawTarget *aDT);

  // The caller needs to call Finish if drawable is non-zero when
  // they are done with the context. This is currently explicit
  // instead of happening implicitly in the destructor to make
  // what's happening in the caller more clear. It also
  // let's you resume using the DrawTarget in the same scope.
  void Finish();

  ~BorrowedXlibDrawable() {
    MOZ_ASSERT(!mDrawable);
  }

  Display *GetDisplay() const { return mDisplay; }
  Drawable GetDrawable() const { return mDrawable; }
  Screen *GetScreen() const { return mScreen; }
  Visual *GetVisual() const { return mVisual; }
  IntSize GetSize() const { return mSize; }
  Point GetOffset() const { return mOffset; }

  XRenderPictFormat* GetXRenderFormat() const { return mXRenderFormat; }

private:
  DrawTarget *mDT;
  Display *mDisplay;
  Drawable mDrawable;
  Screen *mScreen;
  Visual *mVisual;
  XRenderPictFormat *mXRenderFormat;
  IntSize mSize;
  Point mOffset;
};
#endif

#ifdef XP_DARWIN
/* This is a helper class that let's you borrow a CGContextRef from a
 * DrawTargetCG. This is used for drawing themed widgets.
 *
 * Callers should check the cg member after constructing the object
 * to see if it succeeded. The DrawTarget should not be used while
 * the context is borrowed. */
class BorrowedCGContext
{
public:
  BorrowedCGContext()
    : cg(nullptr)
    , mDT(nullptr)
  { }

  explicit BorrowedCGContext(DrawTarget *aDT)
    : mDT(aDT)
  {
    MOZ_ASSERT(aDT, "Caller should check for nullptr");
    cg = BorrowCGContextFromDrawTarget(aDT);
  }

  // We can optionally Init after construction in
  // case we don't know what the DT will be at construction
  // time.
  CGContextRef Init(DrawTarget *aDT)
  {
    MOZ_ASSERT(aDT, "Caller should check for nullptr");
    MOZ_ASSERT(!mDT, "Can't initialize twice!");
    mDT = aDT;
    cg = BorrowCGContextFromDrawTarget(aDT);
    return cg;
  }

  // The caller needs to call Finish if cg is non-null when
  // they are done with the context. This is currently explicit
  // instead of happening implicitly in the destructor to make
  // what's happening in the caller more clear. It also
  // let's you resume using the DrawTarget in the same scope.
  void Finish()
  {
    if (cg) {
      ReturnCGContextToDrawTarget(mDT, cg);
      cg = nullptr;
    }
  }

  ~BorrowedCGContext() {
    MOZ_ASSERT(!cg);
  }

  CGContextRef cg;
private:
#ifdef USE_SKIA
  static CGContextRef BorrowCGContextFromDrawTarget(DrawTarget *aDT);
  static void ReturnCGContextToDrawTarget(DrawTarget *aDT, CGContextRef cg);
#else
  static CGContextRef BorrowCGContextFromDrawTarget(DrawTarget *aDT) {
    MOZ_CRASH("Not supported without Skia");
  }

  static void ReturnCGContextToDrawTarget(DrawTarget *aDT, CGContextRef cg) {
    MOZ_CRASH("not supported without Skia");
  }
#endif
  DrawTarget *mDT;
};
#endif

} // namespace gfx
} // namespace mozilla

#endif // _MOZILLA_GFX_BORROWED_CONTEXT_H