Editor: Fix block for offset calculation

Take block bounding rects into account, when calculating the row count
or the center visible line.

Change-Id: If933828867df25920eeb56359e9a42a8b95d9c6d
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/texteditor/texteditor.cpp

@@ -4692,8 +4692,8 @@ QTextBlock TextEditorWidgetPrivate::nextVisibleBlock(const QTextBlock &block) co
 
 void TextEditorWidgetPrivate::cleanupAnnotationCache()
 {
-    const int firstVisibleBlock = q->firstVisibleLine();
-    const int lastVisibleBlock = q->lastVisibleLine();
+    const int firstVisibleBlock = q->firstVisibleBlockNumber();
+    const int lastVisibleBlock = q->lastVisibleBlockNumber();
     auto lineIsVisble = [&](int blockNumber){
         auto behindFirstVisibleBlock = [&](){
             return firstVisibleBlock >= 0 && blockNumber >= firstVisibleBlock;
@@ -8107,8 +8107,26 @@ int TextEditorWidget::columnCount() const
 
 int TextEditorWidget::rowCount() const
 {
-    QFontMetricsF fm(font());
-    return viewport()->rect().height() / fm.lineSpacing();
+    int height = viewport()->rect().height();
+    int lineCount = 0;
+    QTextBlock block = firstVisibleBlock();
+    while (block.isValid()) {
+        height -= blockBoundingRect(block).height();
+        if (height < 0) {
+            const int blockLineCount = block.layout()->lineCount();
+            for (int i = 0; i < blockLineCount; ++i) {
+                ++lineCount;
+                const QTextLine line = block.layout()->lineAt(i);
+                height += line.rect().height();
+                if (height >= 0)
+                    break;
+            }
+            return lineCount;
+        }
+        lineCount += block.layout()->lineCount();
+        block = block.next();
+    }
+    return lineCount;
 }
 
 /**
@@ -8254,6 +8272,18 @@ QTextBlock TextEditorWidget::blockForVisibleRow(int row) const
 
 }
 
+QTextBlock TextEditorWidget::blockForVerticalOffset(int offset) const
+{
+    QTextBlock block = firstVisibleBlock();
+    while (block.isValid()) {
+        offset -= blockBoundingRect(block).height();
+        if (offset < 0)
+            return block;
+        block = block.next();
+    }
+    return block;
+}
+
 void TextEditorWidget::invokeAssist(AssistKind kind, IAssistProvider *provider)
 {
     if (kind == QuickFix && d->m_snippetOverlay->isVisible()) {
@@ -8373,28 +8403,28 @@ void TextEditorWidget::configureGenericHighlighter()
     updateEditorInfoBar(this);
 }
 
-int TextEditorWidget::lineForVisibleRow(int row) const
+int TextEditorWidget::blockNumberForVisibleRow(int row) const
 {
     QTextBlock block = blockForVisibleRow(row);
     return block.isValid() ? block.blockNumber() : -1;
 }
 
-int TextEditorWidget::firstVisibleLine() const
+int TextEditorWidget::firstVisibleBlockNumber() const
 {
-    return lineForVisibleRow(0);
+    return blockNumberForVisibleRow(0);
 }
 
-int TextEditorWidget::lastVisibleLine() const
+int TextEditorWidget::lastVisibleBlockNumber() const
 {
-    QTextBlock block = blockForVisibleRow(rowCount() - 1);
+    QTextBlock block = blockForVerticalOffset(viewport()->height() - 1);
     if (!block.isValid())
         block.previous();
     return block.isValid() ? block.blockNumber() : -1;
 }
 
-int TextEditorWidget::centerVisibleLine() const
+int TextEditorWidget::centerVisibleBlockNumber() const
 {
-    QTextBlock block = blockForVisibleRow(rowCount() / 2);
+    QTextBlock block = blockForVerticalOffset(viewport()->height() / 2);
     if (!block.isValid())
         block.previous();
     return block.isValid() ? block.blockNumber() : -1;

src/plugins/texteditor/texteditor.h

@@ -453,14 +453,14 @@ public:
      *
      * Any invalid row will return -1 as line number.
      */
-    int lineForVisibleRow(int row) const;
+    int blockNumberForVisibleRow(int row) const;
 
     /*! Returns the first visible line of the document. */
-    int firstVisibleLine() const;
+    int firstVisibleBlockNumber() const;
     /*! Returns the last visible line of the document. */
-    int lastVisibleLine() const;
+    int lastVisibleBlockNumber() const;
     /*! Returns the line visible closest to the vertical center of the editor. */
-    int centerVisibleLine() const;
+    int centerVisibleBlockNumber() const;
 
     Core::HighlightScrollBarController *highlightScrollBarController() const;
 
@@ -472,6 +472,7 @@ signals:
 
 protected:
     QTextBlock blockForVisibleRow(int row) const;
+    QTextBlock blockForVerticalOffset(int offset) const;
     bool event(QEvent *e) override;
     void inputMethodEvent(QInputMethodEvent *e) override;
     void keyPressEvent(QKeyEvent *e) override;

src/plugins/vcsbase/vcsbaseeditor.cpp

@@ -1303,14 +1303,14 @@ int VcsBaseEditor::lineNumberOfCurrentEditor(const QString &currentFile)
     const BaseTextEditor *eda = qobject_cast<const BaseTextEditor *>(ed);
     if (!eda)
         return -1;
-    const int cursorLine = eda->currentLine();
+    const int cursorLine = eda->textCursor().blockNumber();
     auto const edw = qobject_cast<const TextEditorWidget *>(ed->widget());
     if (edw) {
-        const int firstLine = edw->firstVisibleLine();
-        const int lastLine = edw->lastVisibleLine();
+        const int firstLine = edw->firstVisibleBlockNumber();
+        const int lastLine = edw->lastVisibleBlockNumber();
         if (firstLine <= cursorLine && cursorLine < lastLine)
             return cursorLine;
-        return edw->centerVisibleLine();
+        return edw->centerVisibleBlockNumber();
     }
     return cursorLine;
 }