1 files changed, 75 insertions, 0 deletions
diff --git a/layout/generic/nsILineIterator.cpp b/layout/generic/nsILineIterator.cpp
new file mode 100644
index 0000000000..7a340ad4c6
--- /dev/null
+++ b/layout/generic/nsILineIterator.cpp
@@ -0,0 +1,75 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#include "nsILineIterator.h"
+#include "nsIFrame.h"
+
+namespace mozilla {
+
+void LineFrameFinder::Scan(nsIFrame* aFrame) {
+  if (mDone) {
+    return;
+  }
+
+  if (!mFirstFrame) {
+    mFirstFrame = aFrame;
+  }
+
+  const LogicalRect rect = aFrame->GetLogicalRect(mWM, mContainerSize);
+  if (rect.ISize(mWM) == 0) {
+    return;
+  }
+  // If pos.I() is inside this frame - this is it
+  if (rect.IStart(mWM) <= mPos.I(mWM) && rect.IEnd(mWM) > mPos.I(mWM)) {
+    mClosestFromStart = mClosestFromEnd = aFrame;
+    mDone = true;
+    return;
+  }
+  if (rect.IStart(mWM) < mPos.I(mWM)) {
+    if (!mClosestFromStart ||
+        rect.IEnd(mWM) >
+            mClosestFromStart->GetLogicalRect(mWM, mContainerSize).IEnd(mWM)) {
+      mClosestFromStart = aFrame;
+    }
+  } else {
+    if (!mClosestFromEnd ||
+        rect.IStart(mWM) <
+            mClosestFromEnd->GetLogicalRect(mWM, mContainerSize).IStart(mWM)) {
+      mClosestFromEnd = aFrame;
+    }
+  }
+}
+
+void LineFrameFinder::Finish(nsIFrame** aFrameFound,
+                             bool* aPosIsBeforeFirstFrame,
+                             bool* aPosIsAfterLastFrame) {
+  if (!mClosestFromStart && !mClosestFromEnd) {
+    // All frames were zero-width. Just take the first one.
+    mClosestFromStart = mClosestFromEnd = mFirstFrame;
+  }
+  *aPosIsBeforeFirstFrame = mIsReversed ? !mClosestFromEnd : !mClosestFromStart;
+  *aPosIsAfterLastFrame = mIsReversed ? !mClosestFromStart : !mClosestFromEnd;
+  if (mClosestFromStart == mClosestFromEnd) {
+    *aFrameFound = mClosestFromStart;
+  } else if (!mClosestFromStart) {
+    *aFrameFound = mClosestFromEnd;
+  } else if (!mClosestFromEnd) {
+    *aFrameFound = mClosestFromStart;
+  } else {  // we're between two frames
+    nscoord delta =
+        mClosestFromEnd->GetLogicalRect(mWM, mContainerSize).IStart(mWM) -
+        mClosestFromStart->GetLogicalRect(mWM, mContainerSize).IEnd(mWM);
+    if (mPos.I(mWM) <
+        mClosestFromStart->GetLogicalRect(mWM, mContainerSize).IEnd(mWM) +
+            delta / 2) {
+      *aFrameFound = mClosestFromStart;
+    } else {
+      *aFrameFound = mClosestFromEnd;
+    }
+  }
+}
+
+}  // namespace mozilla