GTK file chooser image preview support added. #2968

Thanks to Chromium code.
Also fixed build on GCC / Linux.

Telegram/SourceFiles/core/lambda.h

@@ -501,9 +501,9 @@ class guard {
 public:
 	using return_type = typename lambda_type<Lambda>::return_type;
 
-	template <typename ...PointersAndLambda>
+	template <typename Pointer, typename Other, typename ...PointersAndLambda>
-	inline guard(PointersAndLambda&&... qobjectsAndLambda) : _data(std::make_unique<guard_data<N, Lambda>>(std::forward<PointersAndLambda>(qobjectsAndLambda)...)) {
+	inline guard(Pointer &&qobject, Other &&other, PointersAndLambda&&... qobjectsAndLambda) : _data(std::make_unique<guard_data<N, Lambda>>(std::forward<Pointer>(qobject), std::forward<Other>(other), std::forward<PointersAndLambda>(qobjectsAndLambda)...)) {
-		static_assert(sizeof...(PointersAndLambda) == N + 1, "Wrong argument count!");
+		static_assert(1 + 1 + sizeof...(PointersAndLambda) == N + 1, "Wrong argument count!");
 	}
 
 	inline guard(const guard &other) : _data(std::make_unique<guard_data<N, Lambda>>(static_cast<const guard_data<N, Lambda> &>(*other._data))) {

Telegram/SourceFiles/platform/linux/file_dialog_linux.cpp

@@ -31,6 +31,19 @@ QStringList qt_make_filter_list(const QString &filter);
 
 namespace Platform {
 namespace FileDialog {
+namespace {
+
+// GTK file chooser image preview: thanks to Chromium
+
+// The size of the preview we display for selected image files. We set height
+// larger than width because generally there is more free space vertically
+// than horiztonally (setting the preview image will alway expand the width of
+// the dialog, but usually not the height). The image's aspect ratio will always
+// be preserved.
+constexpr auto kPreviewWidth = 256;
+constexpr auto kPreviewHeight = 512;
+
+} // namespace
 
 using Type = ::FileDialog::internal::Type;
 
@@ -70,6 +83,11 @@ bool Supported() {
 		&& (Libs::gtk_file_filter_new != nullptr);
 }
 
+bool PreviewSupported() {
+	return Supported()
+		&& (Libs::gdk_pixbuf_new_from_file_at_size != nullptr);
+}
+
 bool Get(QStringList &files, QByteArray &remoteContent, const QString &caption, const QString &filter, Type type, QString startFile) {
 	auto parent = App::wnd() ? App::wnd()->filedialogParent() : nullptr;
 	internal::GtkFileDialog dialog(parent, caption, QString(), filter);
@@ -117,7 +135,12 @@ namespace internal {
 
 QGtkDialog::QGtkDialog(GtkWidget *gtkWidget) : gtkWidget(gtkWidget) {
 	Libs::g_signal_connect_swapped_helper(Libs::g_object_cast(gtkWidget), "response", GCallback(onResponse), this);
-	Libs::g_signal_connect_helper(Libs::g_object_cast(gtkWidget), "delete-event", GCallback(Libs::gtk_widget_hide_on_delete), NULL);
+	Libs::g_signal_connect_helper(Libs::g_object_cast(gtkWidget), "delete-event", GCallback(Libs::gtk_widget_hide_on_delete), nullptr);
+	if (PreviewSupported()) {
+		_preview = Libs::gtk_image_new();
+		Libs::g_signal_connect_swapped_helper(Libs::g_object_cast(gtkWidget), "update-preview", GCallback(onUpdatePreview), this);
+		Libs::gtk_file_chooser_set_preview_widget(Libs::gtk_file_chooser_cast(gtkWidget), _preview);
+	}
 }
 
 QGtkDialog::~QGtkDialog() {
@@ -179,6 +202,32 @@ void QGtkDialog::onResponse(QGtkDialog *dialog, int response) {
 		emit dialog->reject();
 }
 
+void QGtkDialog::onUpdatePreview(QGtkDialog* dialog) {
+	auto filename = Libs::gtk_file_chooser_get_preview_filename(Libs::gtk_file_chooser_cast(dialog->gtkWidget));
+	if (!filename) {
+		Libs::gtk_file_chooser_set_preview_widget_active(Libs::gtk_file_chooser_cast(dialog->gtkWidget), false);
+		return;
+	}
+
+	// Don't attempt to open anything which isn't a regular file. If a named pipe,
+	// this may hang. See https://crbug.com/534754.
+	struct stat stat_buf;
+	if (stat(filename, &stat_buf) != 0 || !S_ISREG(stat_buf.st_mode)) {
+		Libs::g_free(filename);
+		Libs::gtk_file_chooser_set_preview_widget_active(Libs::gtk_file_chooser_cast(dialog->gtkWidget), false);
+		return;
+	}
+
+	// This will preserve the image's aspect ratio.
+	auto pixbuf = Libs::gdk_pixbuf_new_from_file_at_size(filename, kPreviewWidth, kPreviewHeight, nullptr);
+	Libs::g_free(filename);
+	if (pixbuf) {
+		Libs::gtk_image_set_from_pixbuf(Libs::gtk_image_cast(dialog->_preview), pixbuf);
+		Libs::g_object_unref(pixbuf);
+	}
+	Libs::gtk_file_chooser_set_preview_widget_active(Libs::gtk_file_chooser_cast(dialog->gtkWidget), pixbuf ? true : false);
+}
+
 void QGtkDialog::onParentWindowDestroyed() {
 	// The Gtk*DialogHelper classes own this object. Make sure the parent doesn't delete it.
 	setParent(nullptr);

Telegram/SourceFiles/platform/linux/file_dialog_linux.h

@@ -48,42 +48,44 @@ namespace internal {
 // We need to be able to work with gtk2 and gtk3, because
 // we use gtk3 to work with appindicator3.
 class QGtkDialog : public QWindow {
-    Q_OBJECT
+	Q_OBJECT
 
 public:
-    QGtkDialog(GtkWidget *gtkWidget);
+	QGtkDialog(GtkWidget *gtkWidget);
-    ~QGtkDialog();
+	~QGtkDialog();
 
-    GtkDialog *gtkDialog() const;
+	GtkDialog *gtkDialog() const;
 
-    void exec();
+	void exec();
-    void show(Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent);
+	void show(Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent);
-    void hide();
+	void hide();
 
 signals:
-    void accept();
+	void accept();
-    void reject();
+	void reject();
 
 protected:
-    static void onResponse(QGtkDialog *dialog, int response);
+	static void onResponse(QGtkDialog *dialog, int response);
+	static void onUpdatePreview(QGtkDialog *dialog);
 
 private slots:
-    void onParentWindowDestroyed();
+	void onParentWindowDestroyed();
 
 private:
-    GtkWidget *gtkWidget;
+	GtkWidget *gtkWidget;
+	GtkWidget *_preview = nullptr;
 
 };
 
 class GtkFileDialog : public QDialog {
-    Q_OBJECT
+	Q_OBJECT
 
 public:
-    GtkFileDialog(QWidget *parent = Q_NULLPTR,
+	GtkFileDialog(QWidget *parent = Q_NULLPTR,
-				  const QString &caption = QString(),
+		const QString &caption = QString(),
-                  const QString &directory = QString(),
+		const QString &directory = QString(),
-                  const QString &filter = QString());
+		const QString &filter = QString());
-    ~GtkFileDialog();
+	~GtkFileDialog();
 
 	void setVisible(bool visible) override;
 
@@ -104,26 +106,26 @@ public:
 		}
 	}
 
-    int exec() override;
+	int exec() override;
 
-    bool defaultNameFilterDisables() const;
+	bool defaultNameFilterDisables() const;
-    void setDirectory(const QString &directory);
+	void setDirectory(const QString &directory);
-    QDir directory() const;
+	QDir directory() const;
-    void selectFile(const QString &filename);
+	void selectFile(const QString &filename);
-    QStringList selectedFiles() const;
+	QStringList selectedFiles() const;
-    void setFilter();
+	void setFilter();
-    void selectNameFilter(const QString &filter);
+	void selectNameFilter(const QString &filter);
-    QString selectedNameFilter() const;
+	QString selectedNameFilter() const;
 
 private slots:
-    void onAccepted();
+	void onAccepted();
 	void onRejected();
 
 private:
-    static void onSelectionChanged(GtkDialog *dialog, GtkFileDialog *helper);
+	static void onSelectionChanged(GtkDialog *dialog, GtkFileDialog *helper);
-    static void onCurrentFolderChanged(GtkFileDialog *helper);
+	static void onCurrentFolderChanged(GtkFileDialog *helper);
-    void applyOptions();
+	void applyOptions();
-    void setNameFilters(const QStringList &filters);
+	void setNameFilters(const QStringList &filters);
 
 	void showHelper(Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent);
 	void hideHelper();
@@ -137,11 +139,11 @@ private:
 	QFileDialog::AcceptMode _acceptMode = QFileDialog::AcceptOpen;
 	QFileDialog::FileMode _fileMode = QFileDialog::ExistingFile;
 
-    QString _dir;
+	QString _dir;
-    QStringList _selection;
+	QStringList _selection;
-    QHash<QString, GtkFileFilter*> _filters;
+	QHash<QString, GtkFileFilter*> _filters;
-    QHash<GtkFileFilter*, QString> _filterNames;
+	QHash<GtkFileFilter*, QString> _filterNames;
-    QScopedPointer<QGtkDialog> d;
+	QScopedPointer<QGtkDialog> d;
 };
 
 } // namespace internal

Telegram/SourceFiles/platform/linux/linux_libs.cpp

@@ -67,6 +67,7 @@ bool setupGtkBase(QLibrary &lib_gtk) {
 	if (!load(lib_gtk, "gtk_clipboard_store", gtk_clipboard_store)) return false;
 	if (!load(lib_gtk, "gtk_file_chooser_dialog_new", gtk_file_chooser_dialog_new)) return false;
 	if (!load(lib_gtk, "gtk_file_chooser_get_type", gtk_file_chooser_get_type)) return false;
+	if (!load(lib_gtk, "gtk_image_get_type", gtk_image_get_type)) return false;
 	if (!load(lib_gtk, "gtk_file_chooser_set_current_folder", gtk_file_chooser_set_current_folder)) return false;
 	if (!load(lib_gtk, "gtk_file_chooser_get_current_folder", gtk_file_chooser_get_current_folder)) return false;
 	if (!load(lib_gtk, "gtk_file_chooser_set_current_name", gtk_file_chooser_set_current_name)) return false;
@@ -84,7 +85,12 @@ bool setupGtkBase(QLibrary &lib_gtk) {
 	if (!load(lib_gtk, "gtk_file_filter_set_name", gtk_file_filter_set_name)) return false;
 	if (!load(lib_gtk, "gtk_file_filter_add_pattern", gtk_file_filter_add_pattern)) return false;
 	if (!load(lib_gtk, "gtk_file_chooser_add_filter", gtk_file_chooser_add_filter)) return false;
+	if (!load(lib_gtk, "gtk_file_chooser_set_preview_widget", gtk_file_chooser_set_preview_widget)) return false;
+	if (!load(lib_gtk, "gtk_file_chooser_get_preview_filename", gtk_file_chooser_get_preview_filename)) return false;
+	if (!load(lib_gtk, "gtk_file_chooser_set_preview_widget_active", gtk_file_chooser_set_preview_widget_active)) return false;
 	if (!load(lib_gtk, "gtk_file_filter_new", gtk_file_filter_new)) return false;
+	if (!load(lib_gtk, "gtk_image_new", gtk_image_new)) return false;
+	if (!load(lib_gtk, "gtk_image_set_from_pixbuf", gtk_image_set_from_pixbuf)) return false;
 
 	if (!load(lib_gtk, "gdk_window_set_modal_hint", gdk_window_set_modal_hint)) return false;
 	if (!load(lib_gtk, "gdk_window_focus", gdk_window_focus)) return false;
@@ -149,6 +155,7 @@ f_gtk_clipboard_get gtk_clipboard_get = nullptr;
 f_gtk_clipboard_store gtk_clipboard_store = nullptr;
 f_gtk_file_chooser_dialog_new gtk_file_chooser_dialog_new = nullptr;
 f_gtk_file_chooser_get_type gtk_file_chooser_get_type = nullptr;
+f_gtk_image_get_type gtk_image_get_type = nullptr;
 f_gtk_file_chooser_set_current_folder gtk_file_chooser_set_current_folder = nullptr;
 f_gtk_file_chooser_get_current_folder gtk_file_chooser_get_current_folder = nullptr;
 f_gtk_file_chooser_set_current_name gtk_file_chooser_set_current_name = nullptr;
@@ -166,7 +173,12 @@ f_gtk_file_chooser_remove_filter gtk_file_chooser_remove_filter = nullptr;
 f_gtk_file_filter_set_name gtk_file_filter_set_name = nullptr;
 f_gtk_file_filter_add_pattern gtk_file_filter_add_pattern = nullptr;
 f_gtk_file_chooser_add_filter gtk_file_chooser_add_filter = nullptr;
+f_gtk_file_chooser_set_preview_widget gtk_file_chooser_set_preview_widget = nullptr;
+f_gtk_file_chooser_get_preview_filename gtk_file_chooser_get_preview_filename = nullptr;
+f_gtk_file_chooser_set_preview_widget_active gtk_file_chooser_set_preview_widget_active = nullptr;
 f_gtk_file_filter_new gtk_file_filter_new = nullptr;
+f_gtk_image_new gtk_image_new = nullptr;
+f_gtk_image_set_from_pixbuf gtk_image_set_from_pixbuf = nullptr;
 f_gtk_dialog_get_widget_for_response gtk_dialog_get_widget_for_response = nullptr;
 f_gtk_button_set_label gtk_button_set_label = nullptr;
 f_gtk_button_get_type gtk_button_get_type = nullptr;
@@ -185,6 +197,7 @@ f_app_indicator_set_icon_full app_indicator_set_icon_full = nullptr;
 f_gdk_init_check gdk_init_check = nullptr;
 f_gdk_pixbuf_new_from_data gdk_pixbuf_new_from_data = nullptr;
 f_gdk_pixbuf_new_from_file gdk_pixbuf_new_from_file = nullptr;
+f_gdk_pixbuf_new_from_file_at_size gdk_pixbuf_new_from_file_at_size = nullptr;
 f_gtk_status_icon_new_from_pixbuf gtk_status_icon_new_from_pixbuf = nullptr;
 f_gtk_status_icon_set_from_pixbuf gtk_status_icon_set_from_pixbuf = nullptr;
 f_gtk_status_icon_new_from_file gtk_status_icon_new_from_file = nullptr;
@@ -248,6 +261,7 @@ void start() {
 		load(lib_gtk, "gdk_init_check", gdk_init_check);
 		load(lib_gtk, "gdk_pixbuf_new_from_data", gdk_pixbuf_new_from_data);
 		load(lib_gtk, "gdk_pixbuf_new_from_file", gdk_pixbuf_new_from_file);
+		load(lib_gtk, "gdk_pixbuf_new_from_file_at_size", gdk_pixbuf_new_from_file_at_size);
 		load(lib_gtk, "gtk_status_icon_new_from_pixbuf", gtk_status_icon_new_from_pixbuf);
 		load(lib_gtk, "gtk_status_icon_set_from_pixbuf", gtk_status_icon_set_from_pixbuf);
 		load(lib_gtk, "gtk_status_icon_new_from_file", gtk_status_icon_new_from_file);

Telegram/SourceFiles/platform/linux/linux_libs.h

@@ -112,13 +112,13 @@ extern f_gtk_file_chooser_dialog_new gtk_file_chooser_dialog_new;
 typedef gboolean (*f_gtk_file_chooser_set_current_folder)(GtkFileChooser *chooser, const gchar *filename);
 extern f_gtk_file_chooser_set_current_folder gtk_file_chooser_set_current_folder;
 
-typedef gchar *(*f_gtk_file_chooser_get_current_folder)(GtkFileChooser *chooser);
+typedef gchar* (*f_gtk_file_chooser_get_current_folder)(GtkFileChooser *chooser);
 extern f_gtk_file_chooser_get_current_folder gtk_file_chooser_get_current_folder;
 
 typedef void (*f_gtk_file_chooser_set_current_name)(GtkFileChooser *chooser, const gchar *name);
 extern f_gtk_file_chooser_set_current_name gtk_file_chooser_set_current_name;
 
-typedef gboolean (*f_gtk_file_chooser_select_filename)(GtkFileChooser *chooser, const char *filename);
+typedef gboolean (*f_gtk_file_chooser_select_filename)(GtkFileChooser *chooser, const gchar *filename);
 extern f_gtk_file_chooser_select_filename gtk_file_chooser_select_filename;
 
 typedef GSList* (*f_gtk_file_chooser_get_filenames)(GtkFileChooser *chooser);
@@ -163,9 +163,24 @@ extern f_gtk_file_filter_add_pattern gtk_file_filter_add_pattern;
 typedef void (*f_gtk_file_chooser_add_filter)(GtkFileChooser *chooser, GtkFileFilter *filter);
 extern f_gtk_file_chooser_add_filter gtk_file_chooser_add_filter;
 
+typedef void (*f_gtk_file_chooser_set_preview_widget)(GtkFileChooser *chooser, GtkWidget *preview_widget);
+extern f_gtk_file_chooser_set_preview_widget gtk_file_chooser_set_preview_widget;
+
+typedef gchar* (*f_gtk_file_chooser_get_preview_filename)(GtkFileChooser *chooser);
+extern f_gtk_file_chooser_get_preview_filename gtk_file_chooser_get_preview_filename;
+
+typedef void (*f_gtk_file_chooser_set_preview_widget_active)(GtkFileChooser *chooser, gboolean active);
+extern f_gtk_file_chooser_set_preview_widget_active gtk_file_chooser_set_preview_widget_active;
+
 typedef GtkFileFilter* (*f_gtk_file_filter_new)(void);
 extern f_gtk_file_filter_new gtk_file_filter_new;
 
+typedef GtkWidget* (*f_gtk_image_new)(void);
+extern f_gtk_image_new gtk_image_new;
+
+typedef void (*f_gtk_image_set_from_pixbuf)(GtkImage *image, GdkPixbuf *pixbuf);
+extern f_gtk_image_set_from_pixbuf gtk_image_set_from_pixbuf;
+
 typedef void (*f_gdk_window_set_modal_hint)(GdkWindow *window, gboolean modal);
 extern f_gdk_window_set_modal_hint gdk_window_set_modal_hint;
 
@@ -211,6 +226,14 @@ inline GtkFileChooser *gtk_file_chooser_cast(Object *obj) {
 	return g_type_cic_helper<GtkFileChooser, Object>(obj, gtk_file_chooser_get_type());
 }
 
+typedef GType (*f_gtk_image_get_type)(void) G_GNUC_CONST;
+extern f_gtk_image_get_type gtk_image_get_type;
+
+template <typename Object>
+inline GtkImage *gtk_image_cast(Object *obj) {
+	return g_type_cic_helper<GtkImage, Object>(obj, gtk_image_get_type());
+}
+
 typedef GType (*f_gtk_button_get_type)(void) G_GNUC_CONST;
 extern f_gtk_button_get_type gtk_button_get_type;
 
@@ -279,6 +302,9 @@ extern f_gdk_pixbuf_new_from_data gdk_pixbuf_new_from_data;
 typedef GdkPixbuf* (*f_gdk_pixbuf_new_from_file)(const gchar *filename, GError **error);
 extern f_gdk_pixbuf_new_from_file gdk_pixbuf_new_from_file;
 
+typedef GdkPixbuf* (*f_gdk_pixbuf_new_from_file_at_size)(const gchar *filename, int width, int height, GError **error);
+extern f_gdk_pixbuf_new_from_file_at_size gdk_pixbuf_new_from_file_at_size;
+
 typedef GtkStatusIcon* (*f_gtk_status_icon_new_from_pixbuf)(GdkPixbuf *pixbuf);
 extern f_gtk_status_icon_new_from_pixbuf gtk_status_icon_new_from_pixbuf;
 

Telegram/SourceFiles/platform/linux/main_window_linux.cpp

@@ -378,7 +378,6 @@ bool MainWindow::psHasNativeNotifications() {
 }
 
 void MainWindow::LibsLoaded() {
-	auto cdesktop = Libs::CurrentDesktopStrings();
 	noQtTrayIcon = !DesktopEnvironment::TryQtTrayIcon();
 	tryAppIndicator = !DesktopEnvironment::PreferAppIndicatorTrayIcon();