gfx/src/nsDeviceContext.h@97036ab72558
gfx/src/nsDeviceContext.h
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
1 /* -*- Mode: C++; 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/. */
6 #ifndef _NS_DEVICECONTEXT_H_
7 #define _NS_DEVICECONTEXT_H_
9 #include <stdint.h> // for uint32_t
10 #include <sys/types.h> // for int32_t
11 #include "gfxTypes.h" // for gfxFloat
12 #include "mozilla/Assertions.h" // for MOZ_ASSERT_HELPER2
13 #include "nsAutoPtr.h" // for nsRefPtr
14 #include "nsCOMPtr.h" // for nsCOMPtr
15 #include "nsCoord.h" // for nscoord
16 #include "nsError.h" // for nsresult
17 #include "nsISupports.h" // for NS_INLINE_DECL_REFCOUNTING
18 #include "nsMathUtils.h" // for NS_round
19 #include "nscore.h" // for char16_t, nsAString
20 #include "mozilla/AppUnits.h" // for AppUnits
22 class gfxASurface;
23 class gfxTextPerfMetrics;
24 class gfxUserFontSet;
25 class nsFont;
26 class nsFontCache;
27 class nsFontMetrics;
28 class nsIAtom;
29 class nsIDeviceContextSpec;
30 class nsIScreen;
31 class nsIScreenManager;
32 class nsIWidget;
33 class nsRect;
34 class nsRenderingContext;
36 class nsDeviceContext MOZ_FINAL
37 {
38 public:
39 nsDeviceContext();
41 NS_INLINE_DECL_REFCOUNTING(nsDeviceContext)
43 /**
44 * Initialize the device context from a widget
45 * @param aWidget a widget to initialize the device context from
46 * @return error status
47 */
48 nsresult Init(nsIWidget *aWidget);
50 /**
51 * Initialize the device context from a device context spec
52 * @param aDevSpec the specification of the printing device
53 * @return error status
54 */
55 nsresult InitForPrinting(nsIDeviceContextSpec *aDevSpec);
57 /**
58 * Create a rendering context and initialize it. Only call this
59 * method on device contexts that were initialized for printing.
60 *
61 * @return the new rendering context (guaranteed to be non-null)
62 */
63 already_AddRefed<nsRenderingContext> CreateRenderingContext();
65 /**
66 * Gets the number of app units in one CSS pixel; this number is global,
67 * not unique to each device context.
68 */
69 static int32_t AppUnitsPerCSSPixel() { return mozilla::AppUnitsPerCSSPixel(); }
71 /**
72 * Gets the number of app units in one device pixel; this number
73 * is usually a factor of AppUnitsPerCSSPixel(), although that is
74 * not guaranteed.
75 */
76 int32_t AppUnitsPerDevPixel() const { return mAppUnitsPerDevPixel; }
78 /**
79 * Convert device pixels which is used for gfx/thebes to nearest
80 * (rounded) app units
81 */
82 nscoord GfxUnitsToAppUnits(gfxFloat aGfxUnits) const
83 { return nscoord(NS_round(aGfxUnits * AppUnitsPerDevPixel())); }
85 /**
86 * Convert app units to device pixels which is used for gfx/thebes.
87 */
88 gfxFloat AppUnitsToGfxUnits(nscoord aAppUnits) const
89 { return gfxFloat(aAppUnits) / AppUnitsPerDevPixel(); }
91 /**
92 * Gets the number of app units in one physical inch; this is the
93 * device's DPI times AppUnitsPerDevPixel().
94 */
95 int32_t AppUnitsPerPhysicalInch() const
96 { return mAppUnitsPerPhysicalInch; }
98 /**
99 * Gets the number of app units in one CSS inch; this is
100 * 96 times AppUnitsPerCSSPixel.
101 */
102 static int32_t AppUnitsPerCSSInch() { return mozilla::AppUnitsPerCSSInch(); }
104 /**
105 * Get the unscaled ratio of app units to dev pixels; useful if something
106 * needs to be converted from to unscaled pixels
107 */
108 int32_t UnscaledAppUnitsPerDevPixel() const
109 { return mAppUnitsPerDevNotScaledPixel; }
111 /**
112 * Get the nsFontMetrics that describe the properties of
113 * an nsFont.
114 * @param aFont font description to obtain metrics for
115 * @param aLanguage the language of the document
116 * @param aMetrics out parameter for font metrics
117 * @param aUserFontSet user font set
118 * @return error status
119 */
120 nsresult GetMetricsFor(const nsFont& aFont, nsIAtom* aLanguage,
121 gfxUserFontSet* aUserFontSet,
122 gfxTextPerfMetrics* aTextPerf,
123 nsFontMetrics*& aMetrics);
125 /**
126 * Notification when a font metrics instance created for this device is
127 * about to be deleted
128 */
129 nsresult FontMetricsDeleted(const nsFontMetrics* aFontMetrics);
131 /**
132 * Attempt to free up resources by flushing out any fonts no longer
133 * referenced by anything other than the font cache itself.
134 * @return error status
135 */
136 nsresult FlushFontCache();
138 /**
139 * Return the bit depth of the device.
140 */
141 nsresult GetDepth(uint32_t& aDepth);
143 /**
144 * Get the size of the displayable area of the output device
145 * in app units.
146 * @param aWidth out parameter for width
147 * @param aHeight out parameter for height
148 * @return error status
149 */
150 nsresult GetDeviceSurfaceDimensions(nscoord& aWidth, nscoord& aHeight);
152 /**
153 * Get the size of the content area of the output device in app
154 * units. This corresponds on a screen device, for instance, to
155 * the entire screen.
156 * @param aRect out parameter for full rect. Position (x,y) will
157 * be (0,0) or relative to the primary monitor if
158 * this is not the primary.
159 * @return error status
160 */
161 nsresult GetRect(nsRect& aRect);
163 /**
164 * Get the size of the content area of the output device in app
165 * units. This corresponds on a screen device, for instance, to
166 * the area reported by GetDeviceSurfaceDimensions, minus the
167 * taskbar (Windows) or menubar (Macintosh).
168 * @param aRect out parameter for client rect. Position (x,y) will
169 * be (0,0) adjusted for any upper/left non-client
170 * space if present or relative to the primary
171 * monitor if this is not the primary.
172 * @return error status
173 */
174 nsresult GetClientRect(nsRect& aRect);
176 /**
177 * Inform the output device that output of a document is beginning
178 * Used for print related device contexts. Must be matched 1:1 with
179 * EndDocument() or AbortDocument().
180 *
181 * @param aTitle - title of Document
182 * @param aPrintToFileName - name of file to print to, if nullptr
183 * then don't print to file
184 * @param aStartPage - starting page number (must be greater than zero)
185 * @param aEndPage - ending page number (must be less than or
186 * equal to number of pages)
187 *
188 * @return error status
189 */
190 nsresult BeginDocument(const nsAString& aTitle,
191 char16_t* aPrintToFileName,
192 int32_t aStartPage,
193 int32_t aEndPage);
195 /**
196 * Inform the output device that output of a document is ending.
197 * Used for print related device contexts. Must be matched 1:1 with
198 * BeginDocument()
199 * @return error status
200 */
201 nsresult EndDocument();
203 /**
204 * Inform the output device that output of a document is being aborted.
205 * Must be matched 1:1 with BeginDocument()
206 * @return error status
207 */
208 nsresult AbortDocument();
210 /**
211 * Inform the output device that output of a page is beginning
212 * Used for print related device contexts. Must be matched 1:1 with
213 * EndPage() and within a BeginDocument()/EndDocument() pair.
214 * @return error status
215 */
216 nsresult BeginPage();
218 /**
219 * Inform the output device that output of a page is ending
220 * Used for print related device contexts. Must be matched 1:1 with
221 * BeginPage() and within a BeginDocument()/EndDocument() pair.
222 * @return error status
223 */
224 nsresult EndPage();
226 /**
227 * Check to see if the DPI has changed
228 * @return whether there was actually a change in the DPI (whether
229 * AppUnitsPerDevPixel() or AppUnitsPerPhysicalInch()
230 * changed)
231 */
232 bool CheckDPIChange();
234 /**
235 * Set the pixel scaling factor: all lengths are multiplied by this factor
236 * when we convert them to device pixels. Returns whether the ratio of
237 * app units to dev pixels changed because of the scale factor.
238 */
239 bool SetPixelScale(float aScale);
241 /**
242 * Returns the pixel scaling factor (page zoom factor) applied.
243 */
244 float GetPixelScale() const { return mPixelScale; }
246 /**
247 * True if this device context was created for printing.
248 */
249 bool IsPrinterSurface();
251 private:
252 // Private destructor, to discourage deletion outside of Release():
253 ~nsDeviceContext();
255 void SetDPI();
256 void ComputeClientRectUsingScreen(nsRect *outRect);
257 void ComputeFullAreaUsingScreen(nsRect *outRect);
258 void FindScreen(nsIScreen **outScreen);
259 void CalcPrintingSize();
260 void UpdateScaledAppUnits();
262 nscoord mWidth;
263 nscoord mHeight;
264 uint32_t mDepth;
265 int32_t mAppUnitsPerDevPixel;
266 int32_t mAppUnitsPerDevNotScaledPixel;
267 int32_t mAppUnitsPerPhysicalInch;
268 float mPixelScale;
269 float mPrintingScale;
271 nsFontCache* mFontCache;
272 nsCOMPtr<nsIWidget> mWidget;
273 nsCOMPtr<nsIScreenManager> mScreenManager;
274 nsCOMPtr<nsIDeviceContextSpec> mDeviceContextSpec;
275 nsRefPtr<gfxASurface> mPrintingSurface;
276 #ifdef XP_MACOSX
277 nsRefPtr<gfxASurface> mCachedPrintingSurface;
278 #endif
279 };
281 #endif /* _NS_DEVICECONTEXT_H_ */
