[epiphany] Add a preview widget to "Open..." and "Save..." dialogs. #552 Subsequently, override webkit's "Open.

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 3a625a18e422c5f17b442bd3e76e95283a53f7a8
Author: Que Quotion <quequotion bugmenot com>
Date:   Thu Oct 11 02:45:58 2018 +0900

    Add a preview widget to "Open..." and "Save..." dialogs. #552
    Subsequently, override webkit's "Open..." dialog with epiphany's own.

 embed/ephy-web-view.c           | 57 +++++++++++++++++++++++++++++++++++++++
 lib/widgets/ephy-file-chooser.c | 60 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 117 insertions(+)
---
diff --git a/embed/ephy-web-view.c b/embed/ephy-web-view.c
index f18b8acf0..f9ff26654 100644
--- a/embed/ephy-web-view.c
+++ b/embed/ephy-web-view.c
@@ -31,6 +31,7 @@
 #include "ephy-embed-utils.h"
 #include "ephy-embed.h"
 #include "ephy-favicon-helpers.h"
+#include "ephy-file-chooser.h"
 #include "ephy-file-helpers.h"
 #include "ephy-file-monitor.h"
 #include "ephy-gsb-utils.h"
@@ -300,6 +301,59 @@ popups_manager_hide_all (EphyWebView *view)
   view->shown_popups = NULL;
 }
 
+static void
+open_response_cb (GtkFileChooser           *dialog,
+                  gint                      response,
+                  WebKitFileChooserRequest *request)
+{
+  if (response == GTK_RESPONSE_ACCEPT) {
+    GSList *file_list = gtk_file_chooser_get_filenames (dialog);
+    GPtrArray *file_array = g_ptr_array_new ();
+
+    for (GSList *file = file_list; file; file = g_slist_next (file))
+      g_ptr_array_add (file_array, file->data);
+
+    g_ptr_array_add (file_array, NULL);
+    webkit_file_chooser_request_select_files (request, (const char * const *)file_array->pdata);
+    g_slist_free_full (file_list, g_free);
+    g_ptr_array_free (file_array, FALSE);
+  } else {
+    webkit_file_chooser_request_cancel (request);
+  }
+
+  g_object_unref (request);
+  g_object_unref (dialog);
+}
+
+static gboolean
+ephy_web_view_run_file_chooser (WebKitWebView            *web_view,
+                                WebKitFileChooserRequest *request)
+{
+
+  GtkWidget *toplevel = gtk_widget_get_toplevel (GTK_WIDGET (web_view));
+  GtkFileChooser *dialog;
+  gboolean allows_multiple_selection = webkit_file_chooser_request_get_select_multiple (request);
+  GtkFileFilter *filter = webkit_file_chooser_request_get_mime_types_filter (request);
+
+  dialog = ephy_create_file_chooser (_("Open"),
+                                     GTK_WIDGET (toplevel),
+                                     GTK_FILE_CHOOSER_ACTION_OPEN,
+                                     EPHY_FILE_FILTER_ALL_SUPPORTED);
+
+  if (filter)
+    gtk_file_chooser_set_filter (GTK_FILE_CHOOSER (dialog), filter);
+
+  gtk_file_chooser_set_select_multiple (GTK_FILE_CHOOSER (dialog), allows_multiple_selection);
+
+  g_signal_connect (dialog, "response",
+                    G_CALLBACK (open_response_cb),
+                    g_object_ref (request));
+
+  gtk_native_dialog_show (GTK_NATIVE_DIALOG (dialog));
+
+  return TRUE;
+}
+
 static void
 ephy_web_view_set_popups_allowed (EphyWebView *view,
                                   gboolean     allowed)
@@ -1126,6 +1180,7 @@ ephy_web_view_class_init (EphyWebViewClass *klass)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
   GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+  WebKitWebViewClass *webkit_webview_class = WEBKIT_WEB_VIEW_CLASS (klass);
 
   gobject_class->dispose = ephy_web_view_dispose;
   gobject_class->finalize = ephy_web_view_finalize;
@@ -1136,6 +1191,8 @@ ephy_web_view_class_init (EphyWebViewClass *klass)
   widget_class->button_press_event = ephy_web_view_button_press_event;
   widget_class->key_press_event = ephy_web_view_key_press_event;
 
+  webkit_webview_class->run_file_chooser = ephy_web_view_run_file_chooser;
+
 /**
  * EphyWebView:address:
  *
diff --git a/lib/widgets/ephy-file-chooser.c b/lib/widgets/ephy-file-chooser.c
index a0a53b73e..d27309105 100644
--- a/lib/widgets/ephy-file-chooser.c
+++ b/lib/widgets/ephy-file-chooser.c
@@ -31,7 +31,13 @@
 
 #include <gtk/gtk.h>
 #include <glib/gi18n.h>
+#include <glib/gstdio.h>
 
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#define MAX_PREVIEW_SIZE 180
+#define MAX_PREVIEW_SOURCE_SIZE 4096
 
 static GtkFileFilter *
 ephy_file_chooser_add_pattern_filter (GtkFileChooser *dialog,
@@ -89,6 +95,53 @@ ephy_file_chooser_add_mime_filter (GtkFileChooser *dialog,
   return filth;
 }
 
+static void
+update_preview_cb (GtkFileChooser *file_chooser,
+                   gpointer        data)
+{
+  GtkImage *preview = GTK_IMAGE (data);
+  g_autofree char *filename = gtk_file_chooser_get_preview_filename (file_chooser);
+  gint preview_width = 0;
+  gint preview_height = 0;
+  struct g_stat st_buf;
+  g_autoptr (GdkPixbuf) pixbuf = NULL;
+
+  GdkPixbufFormat *preview_format = gdk_pixbuf_get_file_info (filename,
+                                                              &preview_width,
+                                                              &preview_height);
+
+  if (!filename || g_stat (filename, &st_buf) || (!S_ISREG (st_buf.st_mode))) {
+    gtk_file_chooser_set_preview_widget_active (file_chooser, FALSE);
+    return; // stat failed or file is not regular
+  }
+
+  if (!preview_format ||
+      preview_width <= 0 || preview_height <= 0 ||
+      preview_width > MAX_PREVIEW_SOURCE_SIZE ||
+      preview_height > MAX_PREVIEW_SOURCE_SIZE) {
+    gtk_file_chooser_set_preview_widget_active (file_chooser, FALSE);
+    return; // unpreviewable, 0px, or unsafely large
+  }
+
+  if (preview_width > MAX_PREVIEW_SIZE || preview_height > MAX_PREVIEW_SIZE) {
+    pixbuf = gdk_pixbuf_new_from_file_at_size (filename,
+                                               MAX_PREVIEW_SIZE,
+                                               MAX_PREVIEW_SIZE,
+                                               NULL);
+  } else {
+    pixbuf = gdk_pixbuf_new_from_file (filename, NULL);
+  }
+
+  pixbuf = gdk_pixbuf_apply_embedded_orientation (pixbuf);
+
+  gtk_widget_set_size_request (GTK_WIDGET (preview),
+                               gdk_pixbuf_get_width (pixbuf) + 6,
+                               gdk_pixbuf_get_height (pixbuf) + 6);
+
+  gtk_image_set_from_pixbuf (preview, pixbuf);
+  gtk_file_chooser_set_preview_widget_active (file_chooser, pixbuf != NULL);
+}
+
 GtkFileChooser *
 ephy_create_file_chooser (const char           *title,
                           GtkWidget            *parent,
@@ -98,6 +151,7 @@ ephy_create_file_chooser (const char           *title,
   GtkFileChooser *dialog;
   GtkFileFilter *filter[EPHY_FILE_FILTER_LAST];
   char *downloads_dir;
+  GtkWidget *preview = gtk_image_new ();
 
   g_assert (GTK_IS_WINDOW (parent));
   g_assert (default_filter >= 0 && default_filter <= EPHY_FILE_FILTER_LAST);
@@ -121,6 +175,12 @@ ephy_create_file_chooser (const char           *title,
     gtk_file_chooser_native_set_accept_label (GTK_FILE_CHOOSER_NATIVE (dialog), _("_Save"));
   }
 
+  gtk_file_chooser_set_preview_widget (dialog, preview);
+  gtk_file_chooser_set_use_preview_label (dialog, FALSE);
+  g_signal_connect (dialog, "update-preview",
+                    G_CALLBACK (update_preview_cb),
+                    preview);
+
   if (default_filter != EPHY_FILE_FILTER_NONE) {
     filter[EPHY_FILE_FILTER_ALL_SUPPORTED] =
       ephy_file_chooser_add_mime_filter