Beginnings of a line iterator

git-svn-id: svn://10.0.0.236/trunk@31002 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/layout/generic/nsLineBox.cpp

@@ -202,3 +202,56 @@ nsLineBox::CheckIsBlock() const
   return isBlock == IsBlock();
 }
 #endif
+
+//----------------------------------------------------------------------
+
+static nsLineBox* gDummyLines[1];
+
+nsLineIterator::nsLineIterator()
+{
+  mLines = nsnull;
+  mNumLines = 0;
+  mIndex = 0;
+}
+
+nsresult
+nsLineIterator::Init(nsLineBox* aLines)
+{
+  // Count the lines
+  PRInt32 numLines = 0;
+  nsLineBox* line = aLines;
+  while (line) {
+    numLines++;
+    line = line->mNext;
+  }
+  if (0 == numLines) {
+    // Use gDummyLines so that we don't need null pointer checks in
+    // the accessor methods
+    mLines = gDummyLines;
+    return NS_OK;
+  }
+
+  // Make a linear array of the lines
+  mLines = new nsLineBox*[numLines];
+  if (!mLines) {
+    // Use gDummyLines so that we don't need null pointer checks in
+    // the accessor methods
+    mLines = gDummyLines;
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  nsLineBox** lp = mLines;
+  line = aLines;
+  while (line) {
+    *lp++ = line;
+    line = line->mNext;
+  }
+  mNumLines = numLines;
+  return NS_OK;
+}
+
+nsLineIterator::~nsLineIterator()
+{
+  if (mLines != gDummyLines) {
+    delete [] mLines;
+  }
+}

mozilla/layout/generic/nsLineBox.h

@@ -193,4 +193,46 @@ public:
   nsLineBox* mNext;
 };
 
+//----------------------------------------------------------------------
+
+struct nsLineIterator {
+  nsLineIterator();
+  ~nsLineIterator();
+
+  nsresult Init(nsLineBox* aLines);
+
+  PRInt32 NumLines() const {
+    return mNumLines;
+  }
+
+  nsLineBox* CurrentLine() {
+    return mLines[mIndex];
+  }
+
+  nsLineBox* PrevLine() {
+    if (0 == mIndex) {
+      return nsnull;
+    }
+    return mLines[--mIndex];
+  }
+
+  nsLineBox* NextLine() {
+    if (mIndex >= mNumLines - 1) {
+      return nsnull;
+    }
+    return mLines[++mIndex];
+  }
+
+  nsLineBox* LineAt(PRInt32 aIndex) {
+    if ((aIndex < 0) || (aIndex >= mNumLines)) {
+      return nsnull;
+    }
+    return mLines[aIndex];
+  }
+
+  nsLineBox** mLines;
+  PRInt32 mIndex;
+  PRInt32 mNumLines;
+};
+
 #endif /* nsLineBox_h___ */

mozilla/layout/html/base/src/nsLineBox.cpp

@@ -202,3 +202,56 @@ nsLineBox::CheckIsBlock() const
   return isBlock == IsBlock();
 }
 #endif
+
+//----------------------------------------------------------------------
+
+static nsLineBox* gDummyLines[1];
+
+nsLineIterator::nsLineIterator()
+{
+  mLines = nsnull;
+  mNumLines = 0;
+  mIndex = 0;
+}
+
+nsresult
+nsLineIterator::Init(nsLineBox* aLines)
+{
+  // Count the lines
+  PRInt32 numLines = 0;
+  nsLineBox* line = aLines;
+  while (line) {
+    numLines++;
+    line = line->mNext;
+  }
+  if (0 == numLines) {
+    // Use gDummyLines so that we don't need null pointer checks in
+    // the accessor methods
+    mLines = gDummyLines;
+    return NS_OK;
+  }
+
+  // Make a linear array of the lines
+  mLines = new nsLineBox*[numLines];
+  if (!mLines) {
+    // Use gDummyLines so that we don't need null pointer checks in
+    // the accessor methods
+    mLines = gDummyLines;
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  nsLineBox** lp = mLines;
+  line = aLines;
+  while (line) {
+    *lp++ = line;
+    line = line->mNext;
+  }
+  mNumLines = numLines;
+  return NS_OK;
+}
+
+nsLineIterator::~nsLineIterator()
+{
+  if (mLines != gDummyLines) {
+    delete [] mLines;
+  }
+}

mozilla/layout/html/base/src/nsLineBox.h

@@ -193,4 +193,46 @@ public:
   nsLineBox* mNext;
 };
 
+//----------------------------------------------------------------------
+
+struct nsLineIterator {
+  nsLineIterator();
+  ~nsLineIterator();
+
+  nsresult Init(nsLineBox* aLines);
+
+  PRInt32 NumLines() const {
+    return mNumLines;
+  }
+
+  nsLineBox* CurrentLine() {
+    return mLines[mIndex];
+  }
+
+  nsLineBox* PrevLine() {
+    if (0 == mIndex) {
+      return nsnull;
+    }
+    return mLines[--mIndex];
+  }
+
+  nsLineBox* NextLine() {
+    if (mIndex >= mNumLines - 1) {
+      return nsnull;
+    }
+    return mLines[++mIndex];
+  }
+
+  nsLineBox* LineAt(PRInt32 aIndex) {
+    if ((aIndex < 0) || (aIndex >= mNumLines)) {
+      return nsnull;
+    }
+    return mLines[aIndex];
+  }
+
+  nsLineBox** mLines;
+  PRInt32 mIndex;
+  PRInt32 mNumLines;
+};
+
 #endif /* nsLineBox_h___ */