[gnome-screenshot] Add a back button to take another screenshot

[Cosimo Cecchi <cosimoc src gnome org>]

commit 84be0c3aba941b527be86b17c48c6295f4479489
Author: Daniel Byrne <byrnedj12 gmail com>
Date:   Sun Jul 30 19:50:00 2017 -0700

    Add a back button to take another screenshot
    
    This commit adds a back button so users can take another screenshot when
    launched in interactive mode.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=765941

 src/screenshot-application.c |   25 ++++++++++++++++++++-----
 src/screenshot-dialog.c      |   10 ++++++++--
 src/screenshot-dialog.h      |    5 ++++-
 src/screenshot-dialog.ui     |   21 +++++++++++++++++++++
 4 files changed, 53 insertions(+), 8 deletions(-)
---
diff --git a/src/screenshot-application.c b/src/screenshot-application.c
index 6d6d6d5..672c9ce 100644
--- a/src/screenshot-application.c
+++ b/src/screenshot-application.c
@@ -108,17 +108,22 @@ set_recent_entry (ScreenshotApplication *self)
 }
 
 static void
+screenshot_close_interactive_dialog (ScreenshotApplication *self)
+{
+  ScreenshotDialog *dialog = self->priv->dialog;
+  save_folder_to_settings (self);
+  gtk_widget_destroy (dialog->dialog);
+  g_free (dialog);
+}
+
+static void
 save_pixbuf_handle_success (ScreenshotApplication *self)
 {
   set_recent_entry (self);
 
   if (screenshot_config->interactive)
     {
-      ScreenshotDialog *dialog = self->priv->dialog;
-
-      save_folder_to_settings (self);
-      gtk_widget_destroy (dialog->dialog);
-      g_free (dialog);
+      screenshot_close_interactive_dialog (self);
     }
   else
     {
@@ -382,6 +387,13 @@ screenshot_save_to_file (ScreenshotApplication *self)
 }
 
 static void
+screenshot_back (ScreenshotApplication *self)
+{
+  screenshot_close_interactive_dialog (self);
+  screenshot_show_interactive_dialog (self);
+}
+
+static void
 screenshot_save_to_clipboard (ScreenshotApplication *self)
 {
   GtkClipboard *clipboard;
@@ -406,6 +418,9 @@ screenshot_dialog_response_cb (ScreenshotResponse response,
     case SCREENSHOT_RESPONSE_COPY:
       screenshot_save_to_clipboard (self);
       break;
+    case SCREENSHOT_RESPONSE_BACK:
+      screenshot_back (self);
+      break;
     default:
       g_assert_not_reached ();
       break;
diff --git a/src/screenshot-dialog.c b/src/screenshot-dialog.c
index b7046ed..d5befdc 100644
--- a/src/screenshot-dialog.c
+++ b/src/screenshot-dialog.c
@@ -143,8 +143,12 @@ button_clicked (GtkWidget *button, ScreenshotDialog *dialog)
 {
   ScreenshotResponse res;
 
-  res = (button == dialog->save_button) ? SCREENSHOT_RESPONSE_SAVE
-                                        : SCREENSHOT_RESPONSE_COPY;
+  if (button == dialog->save_button)
+      res = SCREENSHOT_RESPONSE_SAVE;
+  else if (button == dialog->copy_button)
+      res = SCREENSHOT_RESPONSE_COPY;
+  else
+      res = SCREENSHOT_RESPONSE_BACK;
 
   dialog->callback (res, dialog->user_data);
 }
@@ -241,6 +245,8 @@ screenshot_dialog_new (GdkPixbuf              *screenshot,
   g_signal_connect (dialog->save_button, "clicked", G_CALLBACK (button_clicked), dialog);
   dialog->copy_button = GTK_WIDGET (gtk_builder_get_object (ui, "copy_button"));
   g_signal_connect (dialog->copy_button, "clicked", G_CALLBACK (button_clicked), dialog);
+  dialog->back_button = GTK_WIDGET (gtk_builder_get_object (ui, "back_button"));
+  g_signal_connect (dialog->back_button, "clicked", G_CALLBACK (button_clicked), dialog);
 
   setup_drawing_area (dialog, ui);
 
diff --git a/src/screenshot-dialog.h b/src/screenshot-dialog.h
index 45b0641..67bfbd5 100644
--- a/src/screenshot-dialog.h
+++ b/src/screenshot-dialog.h
@@ -24,7 +24,9 @@
 
 typedef enum {
   SCREENSHOT_RESPONSE_SAVE,
-  SCREENSHOT_RESPONSE_COPY
+  SCREENSHOT_RESPONSE_COPY,
+  SCREENSHOT_RESPONSE_BACK
+
 } ScreenshotResponse;
 
 typedef void (*SaveScreenshotCallback) (ScreenshotResponse response, gpointer *user_data);
@@ -38,6 +40,7 @@ typedef struct {
   GtkWidget *filename_entry;
   GtkWidget *save_button;
   GtkWidget *copy_button;
+  GtkWidget *back_button;
 
   gint drag_x;
   gint drag_y;
diff --git a/src/screenshot-dialog.ui b/src/screenshot-dialog.ui
index 01461d7..ed2d620 100644
--- a/src/screenshot-dialog.ui
+++ b/src/screenshot-dialog.ui
@@ -13,6 +13,27 @@
         <property name="can_focus">False</property>
         <property name="show_close_button">True</property>
         <child>
+          <object class="GtkButton" id="back_button">
+            <property name="tooltip_text" translatable="yes">Back</property>
+            <property name="visible">True</property>
+            <property name="can_focus">True</property>
+            <property name="receives_default">True</property>
+            <property name="use_underline">True</property>
+            <style>
+              <class name="image-button"/>
+            </style>
+            <child>
+              <object class="GtkImage">
+                <property name="visible">True</property>
+                <property name="icon_name">go-previous-symbolic</property>
+              </object>
+            </child>
+          </object>
+          <packing>
+            <property name="pack-type">start</property>
+          </packing>
+        </child>
+        <child>
           <object class="GtkButton" id="copy_button">
             <property name="label" translatable="yes">C_opy to Clipboard</property>
             <property name="visible">True</property>