A step out from Harfbuzz (reduce dependency)

Introduce QCharAttributes and use it instead of HB_CharAttributes everywhere in Qt
(in Harfbuzz, the HB_CharAttributes is only used in the text segmentation algorithm
which has been moved from HB to Qt (well, most of it)).
Rename some members to better reflect their meaning,
remember to keep HB_CharAttributes in sync with QCharAttributes.
Also replace HB_ScriptItem with a (temporary) QUnicodeTools::ScriptItem struct
that will be replaced with a more efficient/friendly solution a bit later.

The soft hyphen and the mandatory break detection has been factored out
of the default text breaking algorithm to a higher level in order to refactor
the QCharAttributes bitfields and to optimize the implementation for the common case.

Change-Id: Ieb365623ae954430f1c8b2dfcd65c82973143eec
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

1 files changed, 13 insertions, 12 deletions

diff --git a/src/gui/text/qtextlayout.cpp b/src/gui/text/qtextlayout.cpp
index a49b4112d4..7591b46547 100644
--- a/src/gui/text/qtextlayout.cpp
+++ b/src/gui/text/qtextlayout.cpp
@@ -683,7 +683,7 @@ void QTextLayout::clearLayout()
 */
 int QTextLayout::nextCursorPosition(int oldPos, CursorMode mode) const
 {
-    const HB_CharAttributes *attributes = d->attributes();
+    const QCharAttributes *attributes = d->attributes();
     int len = d->block.isValid() ? d->block.length() - 1
                                  : d->layoutData->string.length();
     Q_ASSERT(len <= d->layoutData->string.length());
@@ -692,7 +692,7 @@ int QTextLayout::nextCursorPosition(int oldPos, CursorMode mode) const
 
     if (mode == SkipCharacters) {
         oldPos++;
-        while (oldPos < len && !attributes[oldPos].charStop)
+        while (oldPos < len && !attributes[oldPos].graphemeBoundary)
             oldPos++;
     } else {
         if (oldPos < len && d->atWordSeparator(oldPos)) {
@@ -719,13 +719,13 @@ int QTextLayout::nextCursorPosition(int oldPos, CursorMode mode) const
 */
 int QTextLayout::previousCursorPosition(int oldPos, CursorMode mode) const
 {
-    const HB_CharAttributes *attributes = d->attributes();
+    const QCharAttributes *attributes = d->attributes();
     if (!attributes || oldPos <= 0 || oldPos > d->layoutData->string.length())
         return oldPos;
 
     if (mode == SkipCharacters) {
         oldPos--;
-        while (oldPos && !attributes[oldPos].charStop)
+        while (oldPos && !attributes[oldPos].graphemeBoundary)
             oldPos--;
     } else {
         while (oldPos && d->atSpace(oldPos-1))
@@ -789,10 +789,10 @@ int QTextLayout::leftCursorPosition(int oldPos) const
 */
 bool QTextLayout::isValidCursorPosition(int pos) const
 {
-    const HB_CharAttributes *attributes = d->attributes();
+    const QCharAttributes *attributes = d->attributes();
     if (!attributes || pos < 0 || pos > (int)d->layoutData->string.length())
         return false;
-    return attributes[pos].charStop;
+    return attributes[pos].graphemeBoundary;
 }
 
 /*!
@@ -1770,7 +1770,7 @@ void QTextLine::layout_helper(int maxGlyphs)
 
     Qt::Alignment alignment = eng->option.alignment();
 
-    const HB_CharAttributes *attributes = eng->attributes();
+    const QCharAttributes *attributes = eng->attributes();
     if (!attributes)
         return;
     lbh.currentPosition = line.from;
@@ -1875,17 +1875,18 @@ void QTextLine::layout_helper(int maxGlyphs)
 
                 if (lbh.currentPosition >= eng->layoutData->string.length()
                     || attributes[lbh.currentPosition].whiteSpace
-                    || attributes[lbh.currentPosition].lineBreakType != HB_NoBreak) {
+                    || attributes[lbh.currentPosition].lineBreak) {
                     sb_or_ws = true;
                     break;
-                } else if (breakany && attributes[lbh.currentPosition].charStop) {
+                } else if (breakany && attributes[lbh.currentPosition].graphemeBoundary) {
                     break;
                 }
             } while (lbh.currentPosition < end);
             lbh.minw = qMax(lbh.tmpData.textWidth, lbh.minw);
 
             if (lbh.currentPosition > 0 && lbh.currentPosition < end
-                && attributes[lbh.currentPosition].lineBreakType == HB_SoftHyphen) {
+                && attributes[lbh.currentPosition].lineBreak
+                && eng->layoutData->string.at(lbh.currentPosition - 1).unicode() == QChar::SoftHyphen) {
                 // if we are splitting up a word because of
                 // a soft hyphen then we ...
                 //
@@ -2605,12 +2606,12 @@ qreal QTextLine::cursorToX(int *cursorPos, Edge edge) const
     int lineEnd = line.from + line.length + line.trailingSpaces;
     int pos = *cursorPos;
     int itm;
-    const HB_CharAttributes *attributes = eng->attributes();
+    const QCharAttributes *attributes = eng->attributes();
     if (!attributes) {
         *cursorPos = 0;
         return x.toReal();
     }
-    while (pos < lineEnd && !attributes[pos].charStop)
+    while (pos < lineEnd && !attributes[pos].graphemeBoundary)
         pos++;
     if (pos == lineEnd) {
         // end of line ensure we have the last item on the line