widget/WidgetUtils.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * vim: sw=2 ts=8 et :
   3  */
   4 /* This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   6  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   7
   8 #include "mozilla/WidgetUtils.h"
   9
  10 namespace mozilla {
  11
  12 gfx::Matrix
  13 ComputeTransformForRotation(const nsIntRect& aBounds,
  14                               ScreenRotation aRotation)
  15 {
  16     gfx::Matrix transform;
  17     static const gfx::Float floatPi = static_cast<gfx::Float>(M_PI);
  18
  19     switch (aRotation) {
  20     case ROTATION_0:
  21         break;
  22     case ROTATION_90:
  23         transform.PreTranslate(aBounds.width, 0);
  24         transform.PreRotate(floatPi / 2);
  25         break;
  26     case ROTATION_180:
  27         transform.PreTranslate(aBounds.width, aBounds.height);
  28         transform.PreRotate(floatPi);
  29         break;
  30     case ROTATION_270:
  31         transform.PreTranslate(0, aBounds.height);
  32         transform.PreRotate(floatPi * 3 / 2);
  33         break;
  34     default:
  35         MOZ_CRASH("Unknown rotation");
  36     }
  37     return transform;
  38 }
  39
  40 gfx::Matrix
  41 ComputeTransformForUnRotation(const nsIntRect& aBounds,
  42                               ScreenRotation aRotation)
  43 {
  44     gfx::Matrix transform;
  45     static const gfx::Float floatPi = static_cast<gfx::Float>(M_PI);
  46
  47     switch (aRotation) {
  48     case ROTATION_0:
  49         break;
  50     case ROTATION_90:
  51         transform.PreTranslate(0, aBounds.height);
  52         transform.PreRotate(floatPi * 3 / 2);
  53         break;
  54     case ROTATION_180:
  55         transform.PreTranslate(aBounds.width, aBounds.height);
  56         transform.PreRotate(floatPi);
  57         break;
  58     case ROTATION_270:
  59         transform.PreTranslate(aBounds.width, 0);
  60         transform.PreRotate(floatPi / 2);
  61         break;
  62     default:
  63         MOZ_CRASH("Unknown rotation");
  64     }
  65     return transform;
  66 }
  67
  68 nsIntRect RotateRect(nsIntRect aRect,
  69                      const nsIntRect& aBounds,
  70                      ScreenRotation aRotation)
  71 {
  72   switch (aRotation) {
  73     case ROTATION_0:
  74       return aRect;
  75     case ROTATION_90:
  76       return nsIntRect(aRect.y,
  77                        aBounds.width - aRect.x - aRect.width,
  78                        aRect.height, aRect.width);
  79     case ROTATION_180:
  80       return nsIntRect(aBounds.width - aRect.x - aRect.width,
  81                        aBounds.height - aRect.y - aRect.height,
  82                        aRect.width, aRect.height);
  83     case ROTATION_270:
  84       return nsIntRect(aBounds.height - aRect.y - aRect.height,
  85                        aRect.x,
  86                        aRect.height, aRect.width);
  87     default:
  88       MOZ_CRASH("Unknown rotation");
  89       return aRect;
  90   }
  91 }
  92 } // namespace mozilla