Core: Refactor file dropping into reusable component

Change-Id: I42d291d8f8c0e76e289e56055044c369e8be8a89
Reviewed-by: David Schulz <david.schulz@digia.com>

src/libs/utils/fileutils.cpp

@@ -36,7 +36,11 @@
 #include <QDir>
 #include <QDebug>
 #include <QDateTime>
+#include <QDragEnterEvent>
+#include <QDropEvent>
 #include <QMessageBox>
+#include <QMimeData>
+#include <QTimer>
 
 #ifdef Q_OS_WIN
 #include <qt_windows.h>
@@ -679,6 +683,72 @@ FileName &FileName::appendString(QChar str)
     return *this;
 }
 
+static bool isDesktopFileManagerDrop(const QMimeData *d, QStringList *files = 0)
+{
+    if (files)
+        files->clear();
+    // Extract dropped files from Mime data.
+    if (!d->hasUrls())
+        return false;
+    const QList<QUrl> urls = d->urls();
+    if (urls.empty())
+        return false;
+    // Try to find local files
+    bool hasFiles = false;
+    const QList<QUrl>::const_iterator cend = urls.constEnd();
+    for (QList<QUrl>::const_iterator it = urls.constBegin(); it != cend; ++it) {
+        const QString fileName = it->toLocalFile();
+        if (!fileName.isEmpty()) {
+            hasFiles = true;
+            if (files)
+                files->push_back(fileName);
+            else
+                break; // No result list, sufficient for checking
+        }
+    }
+    return hasFiles;
+}
+
+FileDropSupport::FileDropSupport(QWidget *parentWidget)
+    : QObject(parentWidget)
+{
+    QTC_ASSERT(parentWidget, return);
+    parentWidget->setAcceptDrops(true);
+    parentWidget->installEventFilter(this);
+}
+
+bool FileDropSupport::eventFilter(QObject *obj, QEvent *event)
+{
+    Q_UNUSED(obj)
+    if (event->type() == QEvent::DragEnter) {
+        auto dee = static_cast<QDragEnterEvent *>(event);
+        if (isDesktopFileManagerDrop(dee->mimeData()))
+            event->accept();
+        else
+            event->ignore();
+    } else if (event->type() == QEvent::Drop) {
+        auto de = static_cast<QDropEvent *>(event);
+        QStringList tempFiles;
+        if (isDesktopFileManagerDrop(de->mimeData(), &tempFiles)) {
+            event->accept();
+            bool needToScheduleEmit = m_files.isEmpty();
+            m_files.append(tempFiles);
+            if (needToScheduleEmit) // otherwise we already have a timer pending
+                QTimer::singleShot(0, this, SLOT(emitFilesDropped()));
+        } else {
+            event->ignore();
+        }
+    }
+    return false;
+}
+
+void FileDropSupport::emitFilesDropped()
+{
+    QTC_ASSERT(!m_files.isEmpty(), return);
+    emit filesDropped(m_files);
+    m_files.clear();
+}
+
 } // namespace Utils
 
 QT_BEGIN_NAMESPACE

src/libs/utils/fileutils.h

@@ -35,6 +35,7 @@
 #include <QCoreApplication>
 #include <QXmlStreamWriter> // Mac.
 #include <QMetaType>
+#include <QStringList>
 
 namespace Utils {class FileName; }
 
@@ -192,6 +193,26 @@ private:
     bool m_autoRemove;
 };
 
+class QTCREATOR_UTILS_EXPORT FileDropSupport : public QObject
+{
+    Q_OBJECT
+public:
+    FileDropSupport(QWidget *parentWidget);
+
+signals:
+    void filesDropped(const QStringList &files);
+
+protected:
+    bool eventFilter(QObject *obj, QEvent *event);
+
+private slots:
+    void emitFilesDropped();
+
+private:
+    QStringList m_files;
+
+};
+
 } // namespace Utils
 
 QT_BEGIN_NAMESPACE

src/plugins/coreplugin/mainwindow.cpp

@@ -74,6 +74,7 @@
 #include <coreplugin/progressmanager/progressmanager_p.h>
 #include <coreplugin/progressmanager/progressview.h>
 #include <coreplugin/settingsdatabase.h>
+#include <utils/fileutils.h>
 #include <utils/historycompleter.h>
 #include <utils/hostosinfo.h>
 #include <utils/qtcassert.h>
@@ -87,7 +88,6 @@
 #include <QTimer>
 #include <QUrl>
 #include <QDir>
-#include <QMimeData>
 
 #include <QApplication>
 #include <QCloseEvent>
@@ -211,7 +211,10 @@ MainWindow::MainWindow() :
         //signal(SIGINT, handleSigInt);
 
     statusBar()->setProperty("p_styled", true);
-    setAcceptDrops(true);
+
+    auto dropSupport = new Utils::FileDropSupport(this);
+    connect(dropSupport, SIGNAL(filesDropped(QStringList)),
+            this, SLOT(openDroppedFiles(QStringList)));
 
 #if defined(Q_OS_MAC)
     MacFullScreen::addFullScreen(this);
@@ -386,61 +389,10 @@ void MainWindow::closeEvent(QCloseEvent *event)
     event->accept();
 }
 
-// Check for desktop file manager file drop events
-
-static bool isDesktopFileManagerDrop(const QMimeData *d, QStringList *files = 0)
+void MainWindow::openDroppedFiles(const QStringList &files)
 {
-    if (files)
-        files->clear();
-    // Extract dropped files from Mime data.
-    if (!d->hasUrls())
-        return false;
-    const QList<QUrl> urls = d->urls();
-    if (urls.empty())
-        return false;
-    // Try to find local files
-    bool hasFiles = false;
-    const QList<QUrl>::const_iterator cend = urls.constEnd();
-    for (QList<QUrl>::const_iterator it = urls.constBegin(); it != cend; ++it) {
-        const QString fileName = it->toLocalFile();
-        if (!fileName.isEmpty()) {
-            hasFiles = true;
-            if (files)
-                files->push_back(fileName);
-            else
-                break; // No result list, sufficient for checking
-        }
-    }
-    return hasFiles;
-}
-
-void MainWindow::dragEnterEvent(QDragEnterEvent *event)
-{
-    if (isDesktopFileManagerDrop(event->mimeData()) && m_filesToOpenDelayed.isEmpty())
-        event->accept();
-    else
-        event->ignore();
-}
-
-void MainWindow::dropEvent(QDropEvent *event)
-{
-    QStringList files;
-    if (isDesktopFileManagerDrop(event->mimeData(), &files)) {
-        event->accept();
-        m_filesToOpenDelayed.append(files);
-        QTimer::singleShot(50, this, SLOT(openDelayedFiles()));
-    } else {
-        event->ignore();
-    }
-}
-
-void MainWindow::openDelayedFiles()
-{
-    if (m_filesToOpenDelayed.isEmpty())
-        return;
     raiseWindow();
-    openFiles(m_filesToOpenDelayed, ICore::SwitchMode);
-    m_filesToOpenDelayed.clear();
+    openFiles(files, ICore::SwitchMode);
 }
 
 IContext *MainWindow::currentContextObject() const

src/plugins/coreplugin/mainwindow.h

@@ -137,8 +137,6 @@ public slots:
 protected:
     virtual void changeEvent(QEvent *e);
     virtual void closeEvent(QCloseEvent *event);
-    virtual void dragEnterEvent(QDragEnterEvent *event);
-    virtual void dropEvent(QDropEvent *event);
 
 private slots:
     void openFile();
@@ -151,7 +149,7 @@ private slots:
     void updateFocusWidget(QWidget *old, QWidget *now);
     void setSidebarVisible(bool visible);
     void destroyVersionDialog();
-    void openDelayedFiles();
+    void openDroppedFiles(const QStringList &files);
     void restoreWindowState();
     void newItemDialogFinished();
 
@@ -213,8 +211,6 @@ private:
 
     QToolButton *m_toggleSideBarButton;
     QColor m_overrideColor;
-
-    QStringList m_filesToOpenDelayed;
 };
 
 } // namespace Internal