layout/generic/nsILineIterator.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "nsILineIterator.h"
   8 #include "nsIFrame.h"
   9
  10 namespace mozilla {
  11
  12 void LineFrameFinder::Scan(nsIFrame* aFrame) {
  13   if (mDone) {
  14     return;
  15   }
  16
  17   if (!mFirstFrame) {
  18     mFirstFrame = aFrame;
  19   }
  20
  21   const LogicalRect rect = aFrame->GetLogicalRect(mWM, mContainerSize);
  22   if (rect.ISize(mWM) == 0) {
  23     return;
  24   }
  25   // If pos.I() is inside this frame - this is it
  26   if (rect.IStart(mWM) <= mPos.I(mWM) && rect.IEnd(mWM) > mPos.I(mWM)) {
  27     mClosestFromStart = mClosestFromEnd = aFrame;
  28     mDone = true;
  29     return;
  30   }
  31   if (rect.IStart(mWM) < mPos.I(mWM)) {
  32     if (!mClosestFromStart ||
  33         rect.IEnd(mWM) >
  34             mClosestFromStart->GetLogicalRect(mWM, mContainerSize).IEnd(mWM)) {
  35       mClosestFromStart = aFrame;
  36     }
  37   } else {
  38     if (!mClosestFromEnd ||
  39         rect.IStart(mWM) <
  40             mClosestFromEnd->GetLogicalRect(mWM, mContainerSize).IStart(mWM)) {
  41       mClosestFromEnd = aFrame;
  42     }
  43   }
  44 }
  45
  46 void LineFrameFinder::Finish(nsIFrame** aFrameFound,
  47                              bool* aPosIsBeforeFirstFrame,
  48                              bool* aPosIsAfterLastFrame) {
  49   if (!mClosestFromStart && !mClosestFromEnd) {
  50     // All frames were zero-width. Just take the first one.
  51     mClosestFromStart = mClosestFromEnd = mFirstFrame;
  52   }
  53   *aPosIsBeforeFirstFrame = mIsReversed ? !mClosestFromEnd : !mClosestFromStart;
  54   *aPosIsAfterLastFrame = mIsReversed ? !mClosestFromStart : !mClosestFromEnd;
  55   if (mClosestFromStart == mClosestFromEnd) {
  56     *aFrameFound = mClosestFromStart;
  57   } else if (!mClosestFromStart) {
  58     *aFrameFound = mClosestFromEnd;
  59   } else if (!mClosestFromEnd) {
  60     *aFrameFound = mClosestFromStart;
  61   } else {  // we're between two frames
  62     nscoord delta =
  63         mClosestFromEnd->GetLogicalRect(mWM, mContainerSize).IStart(mWM) -
  64         mClosestFromStart->GetLogicalRect(mWM, mContainerSize).IEnd(mWM);
  65     if (mPos.I(mWM) <
  66         mClosestFromStart->GetLogicalRect(mWM, mContainerSize).IEnd(mWM) +
  67             delta / 2) {
  68       *aFrameFound = mClosestFromStart;
  69     } else {
  70       *aFrameFound = mClosestFromEnd;
  71     }
  72   }
  73 }
  74
  75 }  // namespace mozilla