From acf678e57ed088f3e56a551cac6c7c3322005750 Mon Sep 17 00:00:00 2001
From: Gunnar Sletta <gunnar.sletta@nokia.com>
Date: Wed, 19 May 2010 07:18:27 +0200
Subject: Use binarysort to find items.

Task: http://bugreports.qt.nokia.com/browse/QTBUG-231
Reviwed-by: Eskil
---
 src/gui/text/qtextengine.cpp | 19 ++++++++++++-------
 src/gui/text/qtextlayout.cpp | 24 +++++++++++++++++-------
 2 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/src/gui/text/qtextengine.cpp b/src/gui/text/qtextengine.cpp
index 5670e29..8d6dd6c 100644
--- a/src/gui/text/qtextengine.cpp
+++ b/src/gui/text/qtextengine.cpp
@@ -1561,14 +1561,19 @@ bool QTextEngine::isRightToLeft() const
 int QTextEngine::findItem(int strPos) const
 {
     itemize();
-
-    // ##### use binary search
-    int item;
-    for (item = layoutData->items.size()-1; item > 0; --item) {
-        if (layoutData->items[item].position <= strPos)
-            break;
+    int left = 0;
+    int right = layoutData->items.size()-1;
+    while(left <= right) {
+        int middle = ((right-left)/2)+left;
+        if (strPos > layoutData->items[middle].position)
+            left = middle+1;
+        else if(strPos < layoutData->items[middle].position)
+            right = middle-1;
+        else {
+            return middle;
+        }
     }
-    return item;
+    return right;
 }
 
 QFixed QTextEngine::width(int from, int len) const
diff --git a/src/gui/text/qtextlayout.cpp b/src/gui/text/qtextlayout.cpp
index 5a11c87..f07c35e 100644
--- a/src/gui/text/qtextlayout.cpp
+++ b/src/gui/text/qtextlayout.cpp
@@ -1217,7 +1217,7 @@ void QTextLayout::draw(QPainter *p, const QPointF &pos, const QVector<FormatRang
 
         bool hasText = (selection.format.foreground().style() != Qt::NoBrush);
         bool hasBackground= (selection.format.background().style() != Qt::NoBrush);
-        
+
         if (hasBackground) {
             selection.format.setProperty(ObjectSelectionBrush, selection.format.property(QTextFormat::BackgroundBrush));
             // don't just clear the property, set an empty brush that overrides a potential
@@ -1727,7 +1727,7 @@ namespace {
     };
 
 inline bool LineBreakHelper::checkFullOtherwiseExtend(QScriptLine &line)
-{        
+{
     LB_DEBUG("possible break width %f, spacew=%f", tmpData.textWidth.toReal(), spaceData.textWidth.toReal());
 
     QFixed newWidth = calculateNewWidth(line);
@@ -1793,13 +1793,23 @@ void QTextLine::layout_helper(int maxGlyphs)
     bool breakany = (wrapMode == QTextOption::WrapAnywhere);
     lbh.manualWrap = (wrapMode == QTextOption::ManualWrap || wrapMode == QTextOption::NoWrap);
 
-    // #### binary search!
     int item = -1;
-    int newItem;
-    for (newItem = eng->layoutData->items.size()-1; newItem > 0; --newItem) {
-        if (eng->layoutData->items[newItem].position <= line.from)
+    int newItem = -1;
+    int left = 0;
+    int right = eng->layoutData->items.size()-1;
+    while(left <= right) {
+        int middle = ((right-left)/2)+left;
+        if (line.from > eng->layoutData->items[middle].position)
+            left = middle+1;
+        else if(line.from < eng->layoutData->items[middle].position)
+            right = middle-1;
+        else {
+            newItem = middle;
             break;
+        }
     }
+    if (newItem == -1)
+        newItem = right;
 
     LB_DEBUG("from: %d: item=%d, total %d, width available %f", line.from, newItem, eng->layoutData->items.size(), line.width.toReal());
 
@@ -1960,7 +1970,7 @@ void QTextLine::layout_helper(int maxGlyphs)
     }
     LB_DEBUG("reached end of line");
     lbh.checkFullOtherwiseExtend(line);
-found:       
+found:
     if (lbh.rightBearing > 0 && !lbh.whiteSpaceOrObject) // If right bearing has not yet been adjusted
         lbh.adjustRightBearing();
     line.textAdvance = line.textWidth;
-- 
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