Support clicking to toggle checkboxes in QTextEdit

Add QAbstractTextDocumentLayout::markerAt(pos) for hit testing.
(Qt Quick TextEdit needs it too.) Finds out whether the position
corresponds to a marker on a paragraph.  I.e. it finds checkboxes in
GitHub-flavored markdown.  This enables editor classes to toggle
checkboxes by clicking them.

Use it in QTextEdit to add the checkbox toggling feature.  Also show the
"pointing finger" cursor when hovering a toggleable checkbox.

Change-Id: I036c967ab45e14c836272eac2cc7c7d652543c89
Reviewed-by: Gatis Paeglis <gatis.paeglis@qt.io>
 
 
 
 
 
 

1 files changed, 38 insertions, 0 deletions

diff --git a/src/widgets/widgets/qwidgettextcontrol.cpp b/src/widgets/widgets/qwidgettextcontrol.cpp
index f85c7cdc6d..af3b03cd9e 100644
--- a/src/widgets/widgets/qwidgettextcontrol.cpp
+++ b/src/widgets/widgets/qwidgettextcontrol.cpp
@@ -1581,6 +1581,11 @@ void QWidgetTextControlPrivate::mousePressEvent(QEvent *e, Qt::MouseButton butto
             e->ignore();
             return;
     }
+    bool wasValid = blockWithMarkerUnderMouse.isValid();
+    blockWithMarkerUnderMouse = q->blockWithMarkerAt(pos);
+    if (wasValid != blockWithMarkerUnderMouse.isValid())
+        emit q->blockMarkerHovered(blockWithMarkerUnderMouse);
+
 
     cursorIsFocusIndicator = false;
     const QTextCursor oldSelection = cursor;
@@ -1599,6 +1604,8 @@ void QWidgetTextControlPrivate::mousePressEvent(QEvent *e, Qt::MouseButton butto
         selectedBlockOnTrippleClick = cursor;
 
         anchorOnMousePress = QString();
+        blockWithMarkerUnderMouse = QTextBlock();
+        emit q->blockMarkerHovered(blockWithMarkerUnderMouse);
 
         trippleClickTimer.stop();
     } else {
@@ -1738,6 +1745,11 @@ void QWidgetTextControlPrivate::mouseMoveEvent(QEvent *e, Qt::MouseButton button
         }
         selectionChanged(true);
         repaintOldAndNewSelection(oldSelection);
+    } else {
+        bool wasValid = blockWithMarkerUnderMouse.isValid();
+        blockWithMarkerUnderMouse = q->blockWithMarkerAt(mousePos);
+        if (wasValid != blockWithMarkerUnderMouse.isValid())
+            emit q->blockMarkerHovered(blockWithMarkerUnderMouse);
     }
 
     sendMouseEventToInputContext(e, QEvent::MouseMove, button, mousePos, modifiers, buttons, globalPos);
@@ -1787,6 +1799,26 @@ void QWidgetTextControlPrivate::mouseReleaseEvent(QEvent *e, Qt::MouseButton but
         emit q->microFocusChanged();
     }
 
+    // toggle any checkbox that the user clicks
+    if ((interactionFlags & Qt::TextEditable) && (button & Qt::LeftButton) &&
+            (blockWithMarkerUnderMouse.isValid()) && !cursor.hasSelection()) {
+        QTextBlock markerBlock = q->blockWithMarkerAt(pos);
+        if (markerBlock == blockWithMarkerUnderMouse) {
+            auto fmt = blockWithMarkerUnderMouse.blockFormat();
+            switch (fmt.marker()) {
+            case QTextBlockFormat::Unchecked :
+                fmt.setMarker(QTextBlockFormat::Checked);
+                break;
+            case QTextBlockFormat::Checked:
+                fmt.setMarker(QTextBlockFormat::Unchecked);
+                break;
+            default:
+                break;
+            }
+            cursor.setBlockFormat(fmt);
+        }
+    }
+
     if (interactionFlags & Qt::LinksAccessibleByMouse) {
         if (!(button & Qt::LeftButton))
             return;
@@ -2385,6 +2417,12 @@ QString QWidgetTextControl::anchorAtCursor() const
     return d->anchorForCursor(d->cursor);
 }
 
+QTextBlock QWidgetTextControl::blockWithMarkerAt(const QPointF &pos) const
+{
+    Q_D(const QWidgetTextControl);
+    return d->doc->documentLayout()->blockWithMarkerAt(pos);
+}
+
 bool QWidgetTextControl::overwriteMode() const
 {
     Q_D(const QWidgetTextControl);