From e540f2eda5bd8f14a90f0b764a4f0b07004aad10 Mon Sep 17 00:00:00 2001
From: Thomas Hartmann <thomas.hartmann@qt.io>
Date: Wed, 4 Jan 2017 13:43:36 +0100
Subject: [PATCH] QmlDesigner: Synchronize selection with cursor position

We always the select the item that contains the cursor,
so the user can use the property editor.
This even works for non visible items.

Change-Id: I5573e6d9be4b478f764ab6960a3b5742136dcee9
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>
---
 .../texteditor/texteditorwidget.cpp           | 25 +++++++++++++++++++
 .../components/texteditor/texteditorwidget.h  |  4 +++
 2 files changed, 29 insertions(+)

diff --git a/src/plugins/qmldesigner/components/texteditor/texteditorwidget.cpp b/src/plugins/qmldesigner/components/texteditor/texteditorwidget.cpp
index 9b5dc32ff8e..ee1a749a492 100644
--- a/src/plugins/qmldesigner/components/texteditor/texteditorwidget.cpp
+++ b/src/plugins/qmldesigner/components/texteditor/texteditorwidget.cpp
@@ -26,6 +26,7 @@
 #include "texteditorwidget.h"
 
 #include <texteditorview.h>
+#include <rewriterview.h>
 
 #include <theming.h>
 
@@ -42,12 +43,20 @@ TextEditorWidget::TextEditorWidget(TextEditorView *textEditorView) : QWidget()
     QBoxLayout *layout = new QVBoxLayout(this);
     layout->setMargin(0);
 
+    m_updateSelectionTimer.setSingleShot(true);
+    m_updateSelectionTimer.setInterval(200);
+
+    connect(&m_updateSelectionTimer, &QTimer::timeout, this, &TextEditorWidget::updateSelectionByCursorPosition);
     setStyleSheet(Theming::replaceCssColors(QString::fromUtf8(Utils::FileReader::fetchQrc(QLatin1String(":/qmldesigner/scrollbar.css")))));
 }
 
 void TextEditorWidget::setTextEditor(TextEditor::BaseTextEditor *textEditor) {
     m_textEditor.reset(textEditor);
     layout()->addWidget(textEditor->editorWidget());
+
+
+    connect(textEditor->editorWidget(), &QPlainTextEdit::cursorPositionChanged,
+            &m_updateSelectionTimer, static_cast<void (QTimer::*)()>(&QTimer::start));
 }
 
 QString TextEditorWidget::contextHelpId() const
@@ -55,4 +64,20 @@ QString TextEditorWidget::contextHelpId() const
     return m_textEditorView->contextHelpId();
 }
 
+void TextEditorWidget::updateSelectionByCursorPosition()
+{
+    /* Because of the timer we have to be careful. */
+    if (!m_textEditorView->model())
+        return;
+
+    const int cursorPosition = m_textEditor->editorWidget()->textCursor().position();
+    RewriterView *rewriterView = m_textEditorView->model()->rewriterView();
+
+    if (rewriterView) {
+        ModelNode modelNode = rewriterView->nodeAtTextCursorPosition(cursorPosition);
+        if (modelNode.isValid())
+            m_textEditorView->setSelectedModelNode(modelNode);
+    }
+}
+
 } // namespace QmlDesigner
diff --git a/src/plugins/qmldesigner/components/texteditor/texteditorwidget.h b/src/plugins/qmldesigner/components/texteditor/texteditorwidget.h
index 5093cfe7ed6..84cd7297f92 100644
--- a/src/plugins/qmldesigner/components/texteditor/texteditorwidget.h
+++ b/src/plugins/qmldesigner/components/texteditor/texteditorwidget.h
@@ -27,6 +27,7 @@
 #include <texteditor/texteditor.h>
 
 #include <QWidget>
+#include <QTimer>
 
 #include <memory>
 
@@ -51,8 +52,11 @@ public:
     QString contextHelpId() const;
 
 private:
+    void updateSelectionByCursorPosition();
+
     std::unique_ptr<TextEditor::BaseTextEditor> m_textEditor;
     QPointer<TextEditorView> m_textEditorView;
+    QTimer m_updateSelectionTimer;
 };
 
 } // namespace QmlDesigner