Revert "Remove the word boundary cache"

[quassel.git] / src / qtui / chatlinemodelitem.cpp

diff --git a/src/qtui/chatlinemodelitem.cpp b/src/qtui/chatlinemodelitem.cpp
index 187ba33..343fb99 100644 (file)
--- a/src/qtui/chatlinemodelitem.cpp
+++ b/src/qtui/chatlinemodelitem.cpp
@@ -18,11 +18,29 @@
  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  ***************************************************************************/
 
+#include <QFontMetrics>
+#include <QTextBoundaryFinder>
+
 #include "chatlinemodelitem.h"
 #include "chatlinemodel.h"
 #include "qtui.h"
 #include "qtuistyle.h"
 
+// This Struct is taken from Harfbuzz. We use it only to calc it's size.
+// we use a shared memory region so we do not have to malloc a buffer area for every line
+typedef struct {
+    /*HB_LineBreakType*/ unsigned lineBreakType  :2;
+    /*HB_Bool*/ unsigned whiteSpace              :1;     /* A unicode whitespace character, except NBSP, ZWNBSP */
+    /*HB_Bool*/ unsigned charStop                :1;     /* Valid cursor position (for left/right arrow) */
+    /*HB_Bool*/ unsigned wordBoundary            :1;
+    /*HB_Bool*/ unsigned sentenceBoundary        :1;
+    unsigned unused                  :2;
+} HB_CharAttributes_Dummy;
+
+
+unsigned char *ChatLineModelItem::TextBoundaryFinderBuffer = (unsigned char *)malloc(512 * sizeof(HB_CharAttributes_Dummy));
+int ChatLineModelItem::TextBoundaryFinderBufferSize = 512 * (sizeof(HB_CharAttributes_Dummy) / sizeof(unsigned char));
+
 // ****************************************
 // the actual ChatLineModelItem
 // ****************************************
@@ -103,6 +121,10 @@ QVariant ChatLineModelItem::contentsData(int role) const {
     return backgroundBrush(UiStyle::Contents, true);
   case ChatLineModel::FormatRole:
     return QVariant::fromValue<UiStyle::FormatList>(_styledMsg.contentsFormatList());
+  case ChatLineModel::WrapListRole:
+    if(_wrapList.isEmpty())
+      computeWrapList();
+    return QVariant::fromValue<ChatLineModel::WrapList>(_wrapList);
   }
   return QVariant();
 }
@@ -122,3 +144,78 @@ QVariant ChatLineModelItem::backgroundBrush(UiStyle::FormatType subelement, bool
     return QVariant::fromValue<QBrush>(fmt.background());
   return QVariant();
 }
+
+void ChatLineModelItem::computeWrapList() const {
+  int length = _styledMsg.plainContents().length();
+  if(!length)
+    return;
+
+  enum Mode { SearchStart, SearchEnd };
+
+  QList<ChatLineModel::Word> wplist;  // use a temp list which we'll later copy into a QVector for efficiency
+  QTextBoundaryFinder finder(QTextBoundaryFinder::Word, _styledMsg.plainContents().unicode(), length,
+                              TextBoundaryFinderBuffer, TextBoundaryFinderBufferSize);
+
+  int idx;
+  int oldidx = 0;
+  bool wordStart = false;
+  bool wordEnd = false;
+  Mode mode = SearchEnd;
+  ChatLineModel::Word word;
+  word.start = 0;
+  qreal wordstartx = 0;
+
+  QTextLayout layout(_styledMsg.plainContents());
+  QTextOption option;
+  option.setWrapMode(QTextOption::NoWrap);
+  layout.setTextOption(option);
+
+  layout.setAdditionalFormats(QtUi::style()->toTextLayoutList(_styledMsg.contentsFormatList(), length, messageLabel()));
+  layout.beginLayout();
+  QTextLine line = layout.createLine();
+  line.setNumColumns(length);
+  layout.endLayout();
+
+  do {
+    idx = finder.toNextBoundary();
+    if(idx < 0) {
+      idx = length;
+      wordStart = false;
+      wordEnd = false;
+      mode = SearchStart;
+    } else {
+      wordStart = finder.boundaryReasons().testFlag(QTextBoundaryFinder::StartWord);
+      wordEnd = finder.boundaryReasons().testFlag(QTextBoundaryFinder::EndWord);
+    }
+
+    //if(flg) qDebug() << idx << mode << wordStart << wordEnd << contents->plainText.left(idx) << contents->plainText.mid(idx);
+
+    if(mode == SearchEnd || (!wordStart && wordEnd)) {
+      if(wordStart || !wordEnd) continue;
+      oldidx = idx;
+      mode = SearchStart;
+      continue;
+    }
+    qreal wordendx = line.cursorToX(oldidx);
+    qreal trailingendx = line.cursorToX(idx);
+    word.endX = wordendx;
+    word.width = wordendx - wordstartx;
+    word.trailing = trailingendx - wordendx;
+    wordstartx = trailingendx;
+    wplist.append(word);
+
+    if(wordStart) {
+      word.start = idx;
+      mode = SearchEnd;
+    }
+    // the part " || (finder.position() == contents->plainText.length())" shouldn't be necessary
+    // but in rare and indeterministic cases Qt states that the end of the text is not a boundary o_O
+  } while(finder.isAtBoundary() || (finder.position() == length));
+
+  // A QVector needs less space than a QList
+  _wrapList.resize(wplist.count());
+  for(int i = 0; i < wplist.count(); i++) {
+    _wrapList[i] = wplist.at(i);
+  }
+}
+