Make accidentally activating the link navigation more difficult

Only checking Ctrl and link availability on mouse release was triggering
the navigation too easily.

Now you have to press and release the mouse on the same link, having
Ctrl pressed all the time. In addition, when changing the text selection
the link is also cleared.

Task-number: QTCREATORBUG-134
Reviewed-by: con

src/plugins/texteditor/basetexteditor.cpp

@@ -648,6 +648,9 @@ void BaseTextEditor::slotSelectionChanged()
         d->m_blockSelectionExtraX = 0;
     if (!d->m_selectBlockAnchor.isNull() && !textCursor().hasSelection())
         d->m_selectBlockAnchor = QTextCursor();
+
+    // Clear any link which might be showing when the selection changes
+    clearLink();
 }
 
 void BaseTextEditor::gotoBlockStart()
@@ -1470,7 +1473,7 @@ BaseTextEditorPrivate::BaseTextEditorPrivate()
     m_requestMarkEnabled(true),
     m_lineSeparatorsAllowed(false),
     m_visibleWrapColumn(0),
-    m_showingLink(false),
+    m_linkPressed(false),
     m_editable(0),
     m_actionHack(0),
     m_inBlockSelectionMode(false),
@@ -2864,35 +2867,11 @@ void BaseTextEditorPrivate::clearVisibleCollapsedBlock()
     }
 }
 
-
 void BaseTextEditor::mouseMoveEvent(QMouseEvent *e)
 {
     d->m_lastEventWasBlockSelectionEvent = (e->modifiers() & Qt::AltModifier);
 
-    bool linkFound = false;
-
-    if (d->m_mouseNavigationEnabled && e->modifiers() & Qt::ControlModifier) {
-        // Link emulation behaviour for 'go to definition'
-        const QTextCursor cursor = cursorForPosition(e->pos());
-
-        // Check that the mouse was actually on the text somewhere
-        bool onText = cursorRect(cursor).right() >= e->x();
-        if (!onText) {
-            QTextCursor nextPos = cursor;
-            nextPos.movePosition(QTextCursor::Right);
-            onText = cursorRect(nextPos).right() >= e->x();
-        }
-
-        const Link link = findLinkAt(cursor, false);
-
-        if (onText && link.isValid()) {
-            showLink(link);
-            linkFound = true;
-        }
-    }
-
-    if (!linkFound)
-        clearLink();
+    updateLink(e);
 
     if (e->buttons() == Qt::NoButton) {
         const QTextBlock collapsedBlock = collapsedBlockAt(e->pos());
@@ -2936,16 +2915,23 @@ void BaseTextEditor::mousePressEvent(QMouseEvent *e)
             toggleBlockVisible(collapsedBlock);
             viewport()->setCursor(Qt::IBeamCursor);
         }
+
+        updateLink(e);
+
+        if (d->m_currentLink.isValid())
+            d->m_linkPressed = true;
     }
     QPlainTextEdit::mousePressEvent(e);
 }
 
 void BaseTextEditor::mouseReleaseEvent(QMouseEvent *e)
 {
-    if (d->m_mouseNavigationEnabled && e->modifiers() & Qt::ControlModifier
+    if (d->m_mouseNavigationEnabled
+        && d->m_linkPressed
+        && e->modifiers() & Qt::ControlModifier
         && !(e->modifiers() & Qt::ShiftModifier)
-        && e->button() == Qt::LeftButton) {
-
+        && e->button() == Qt::LeftButton
+        ) {
         const QTextCursor cursor = cursorForPosition(e->pos());
         if (openLink(findLinkAt(cursor))) {
             clearLink();
@@ -3461,8 +3447,39 @@ bool BaseTextEditor::openLink(const Link &link)
     return openEditorAt(link.fileName, link.line, link.column);
 }
 
+void BaseTextEditor::updateLink(QMouseEvent *e)
+{
+    bool linkFound = false;
+
+    if (d->m_mouseNavigationEnabled && e->modifiers() & Qt::ControlModifier) {
+        // Link emulation behaviour for 'go to definition'
+        const QTextCursor cursor = cursorForPosition(e->pos());
+
+        // Check that the mouse was actually on the text somewhere
+        bool onText = cursorRect(cursor).right() >= e->x();
+        if (!onText) {
+            QTextCursor nextPos = cursor;
+            nextPos.movePosition(QTextCursor::Right);
+            onText = cursorRect(nextPos).right() >= e->x();
+        }
+
+        const Link link = findLinkAt(cursor, false);
+
+        if (onText && link.isValid()) {
+            showLink(link);
+            linkFound = true;
+        }
+    }
+
+    if (!linkFound)
+        clearLink();
+}
+
 void BaseTextEditor::showLink(const Link &link)
 {
+    if (d->m_currentLink == link)
+        return;
+
     QTextEdit::ExtraSelection sel;
     sel.cursor = textCursor();
     sel.cursor.setPosition(link.pos);
@@ -3471,26 +3488,27 @@ void BaseTextEditor::showLink(const Link &link)
     sel.format.setFontUnderline(true);
     setExtraSelections(OtherSelection, QList<QTextEdit::ExtraSelection>() << sel);
     viewport()->setCursor(Qt::PointingHandCursor);
-    d->m_showingLink = true;
+    d->m_currentLink = link;
+    d->m_linkPressed = false;
 }
 
 void BaseTextEditor::clearLink()
 {
-    if (!d->m_showingLink)
+    if (!d->m_currentLink.isValid())
         return;
 
     setExtraSelections(OtherSelection, QList<QTextEdit::ExtraSelection>());
     viewport()->setCursor(Qt::IBeamCursor);
-    d->m_showingLink = false;
+    d->m_currentLink = Link();
+    d->m_linkPressed = false;
 }
 
 void BaseTextEditorPrivate::updateMarksBlock(const QTextBlock &block)
 {
     if (const TextBlockUserData *userData = TextEditDocumentLayout::testUserData(block))
-       foreach (ITextMark *mrk, userData->marks()) {
+        foreach (ITextMark *mrk, userData->marks())
             mrk->updateBlock(block);
 }
-}
 
 void BaseTextEditorPrivate::updateMarksLineNumber()
 {

src/plugins/texteditor/basetexteditor.h

@@ -538,6 +538,9 @@ protected:
         bool isValid() const
         { return !(pos == -1 || length == -1); }
 
+        bool operator==(const Link &other) const
+        { return pos == other.pos && length == other.length; }
+
         int pos;           // Link position
         int length;        // Link length
 
@@ -593,6 +596,7 @@ private:
 
     QTextBlock collapsedBlockAt(const QPoint &pos, QRect *box = 0) const;
 
+    void updateLink(QMouseEvent *e);
     void showLink(const Link &);
     void clearLink();
 

src/plugins/texteditor/basetexteditor_p.h

@@ -204,7 +204,8 @@ public:
     int m_visibleWrapColumn;
 
     QTextCharFormat m_linkFormat;
-    bool m_showingLink;
+    BaseTextEditor::Link m_currentLink;
+    bool m_linkPressed;
 
     QTextCharFormat m_ifdefedOutFormat;