entry: Add a password indicator

This adds a password-indicator property to GtkEntry. When set
on a password entry, the entry shows an icon indicating it is
in password mode, which can be clicked to reveal the text.

We are careful to not interfere with the Caps Lock warning,
which uses the same icon position.

gtk/gtkentry.c

@@ -243,6 +243,8 @@ struct _GtkEntryPrivate
   guint         cache_includes_preedit  : 1;
   guint         caps_lock_warning       : 1;
   guint         caps_lock_warning_shown : 1;
+  guint         password_indicator      : 1;
+  guint         password_indicator_connected : 1;
   guint         change_count            : 8;
   guint         cursor_visible          : 1;
   guint         editing_canceled        : 1; /* Only used by GtkCellRendererText */
@@ -333,6 +335,7 @@ enum {
   PROP_TEXT_LENGTH,
   PROP_INVISIBLE_CHAR_SET,
   PROP_CAPS_LOCK_WARNING,
+  PROP_PASSWORD_INDICATOR,
   PROP_PROGRESS_FRACTION,
   PROP_PROGRESS_PULSE_STEP,
   PROP_PIXBUF_PRIMARY,
@@ -649,6 +652,7 @@ static void         get_frame_size                     (GtkEntry       *entry,
 static void         gtk_entry_move_adjustments         (GtkEntry             *entry);
 static void         gtk_entry_update_cached_style_values(GtkEntry      *entry);
 static gboolean     get_middle_click_paste             (GtkEntry *entry);
+static void         update_password_indicator          (GtkEntry       *entry);
 
 /* GtkTextHandle handlers */
 static void         gtk_entry_handle_drag_started      (GtkTextHandle         *handle,
@@ -1031,7 +1035,7 @@ gtk_entry_class_init (GtkEntryClass *class)
   /**
    * GtkEntry:caps-lock-warning:
    *
-   * Whether password entries will show a warning when Caps Lock is on.
+   * Whether the entry will show a warning when Caps Lock is on in password mode.
    *
    * Note that the warning is shown using a secondary icon, and thus
    * does not work if you are using the secondary icon position for some
@@ -1042,10 +1046,28 @@ gtk_entry_class_init (GtkEntryClass *class)
   entry_props[PROP_CAPS_LOCK_WARNING] =
       g_param_spec_boolean ("caps-lock-warning",
                             P_("Caps Lock warning"),
-                            P_("Whether password entries will show a warning when Caps Lock is on"),
+                            P_("Whether the entry shows a warning when Caps Lock is on in password mode"),
                             TRUE,
                             GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);
 
+  /**
+   * GtkEntry:password-indicator:
+   *
+   * Whether the entry shows an icon to toggle password mode on and off.
+   *
+   * Note that the icon is shown using a secondary icon, and thus
+   * does not work if you are using the secondary icon position for some
+   * other purpose.
+   *
+   * Since: 3.20
+   */
+  entry_props[PROP_PASSWORD_INDICATOR] =
+      g_param_spec_boolean ("password-indicator",
+                            P_("Password indicator"),
+                            P_("Whether the entry shows an icon to toggle password mode"),
+                            FALSE,
+                            GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);
+
   /**
    * GtkEntry:progress-fraction:
    *
@@ -2226,6 +2248,15 @@ gtk_entry_set_property (GObject         *object,
         }
       break;
 
+    case PROP_PASSWORD_INDICATOR:
+      if (priv->password_indicator != g_value_get_boolean (value))
+        {
+          priv->password_indicator = g_value_get_boolean (value);
+          update_password_indicator (entry);
+          g_object_notify_by_pspec (object, pspec);
+        }
+      break;
+
     case PROP_PROGRESS_FRACTION:
       gtk_entry_set_progress_fraction (entry, g_value_get_double (value));
       break;
@@ -2489,6 +2520,10 @@ gtk_entry_get_property (GObject         *object,
       g_value_set_boolean (value, priv->caps_lock_warning);
       break;
 
+    case PROP_PASSWORD_INDICATOR:
+      g_value_set_boolean (value, priv->password_indicator);
+      break;
+
     case PROP_PROGRESS_FRACTION:
       g_value_set_double (value, priv->progress_fraction);
       break;
@@ -2711,6 +2746,8 @@ gtk_entry_init (GtkEntry *entry)
   priv->xalign = 0.0;
   priv->caps_lock_warning = TRUE;
   priv->caps_lock_warning_shown = FALSE;
+  priv->password_indicator = FALSE;
+  priv->password_indicator_connected = FALSE;
   priv->progress_fraction = 0.0;
   priv->progress_pulse_fraction = 0.1;
 
@@ -3402,6 +3439,7 @@ gtk_entry_realize (GtkWidget *widget)
 
   gtk_entry_adjust_scroll (entry);
   gtk_entry_update_primary_selection (entry);
+  update_password_indicator (entry);
 
   /* If the icon positions are already setup, create their windows.
    * Otherwise if they don't exist yet, then construct_icon_info()
@@ -7814,6 +7852,7 @@ gtk_entry_set_visibility (GtkEntry *entry,
     {
       priv->visible = visible;
 
+      update_password_indicator (entry);
       g_object_notify_by_pspec (G_OBJECT (entry), entry_props[PROP_VISIBILITY]);
       gtk_entry_recompute (entry);
     }
@@ -10971,7 +11010,77 @@ gtk_entry_get_placeholder_text (GtkEntry *entry)
   return priv->placeholder_text;
 }
 
-/* Caps Lock warning for password entries */
+/* Caps Lock warning and password indicator */
+
+static void
+password_indicator_show (GtkEntry             *entry,
+                         GtkEntryIconPosition  pos,
+                         GdkEvent             *event,
+                         gpointer              data)
+{
+  GtkEntryPrivate *priv = entry->priv;
+
+  if (pos == GTK_ENTRY_ICON_SECONDARY && priv->password_indicator)
+    gtk_entry_set_visibility (entry, TRUE);
+}
+
+static void
+password_indicator_hide (GtkEntry             *entry,
+                         GtkEntryIconPosition  pos,
+                         GdkEvent             *event,
+                         gpointer              data)
+{
+  GtkEntryPrivate *priv = entry->priv;
+
+  if (pos == GTK_ENTRY_ICON_SECONDARY && priv->password_indicator)
+    gtk_entry_set_visibility (entry, FALSE);
+}
+
+static void
+update_password_indicator (GtkEntry *entry)
+{
+  GtkEntryPrivate *priv = entry->priv;
+
+  if (priv->caps_lock_warning_shown)
+    return;
+
+  if (priv->password_indicator)
+    {
+      if (!priv->password_indicator_connected)
+        {
+          g_signal_connect (entry, "icon-press", G_CALLBACK (password_indicator_show), NULL);
+          g_signal_connect (entry, "icon-release", G_CALLBACK (password_indicator_hide), NULL);
+          priv->password_indicator_connected = TRUE;
+        }
+
+      gtk_entry_set_icon_activatable (entry, GTK_ENTRY_ICON_SECONDARY, TRUE);
+
+      if (gtk_entry_get_display_mode (entry) != DISPLAY_NORMAL)
+        {
+          gtk_entry_set_icon_from_icon_name (entry, GTK_ENTRY_ICON_SECONDARY, "password-invisible");
+          gtk_entry_set_icon_tooltip_text (entry, GTK_ENTRY_ICON_SECONDARY, _("Show text"));
+        }
+      else
+        {
+          gtk_entry_set_icon_from_icon_name (entry, GTK_ENTRY_ICON_SECONDARY, "password-visible");
+          gtk_entry_set_icon_tooltip_text (entry, GTK_ENTRY_ICON_SECONDARY, _("Hide text"));
+        }
+
+    }
+  else
+    {
+      if (priv->password_indicator_connected)
+        {
+          g_signal_handlers_disconnect_by_func (entry, password_indicator_show, NULL);
+          g_signal_handlers_disconnect_by_func (entry, password_indicator_hide, NULL);
+          priv->password_indicator_connected = FALSE;
+        }
+
+      gtk_entry_set_icon_activatable (entry, GTK_ENTRY_ICON_SECONDARY, FALSE);
+      gtk_entry_set_icon_from_icon_name (entry, GTK_ENTRY_ICON_SECONDARY, NULL);
+      gtk_entry_set_icon_tooltip_text (entry, GTK_ENTRY_ICON_SECONDARY, NULL);
+    }
+}
 
 static void
 show_capslock_feedback (GtkEntry    *entry,
@@ -10979,7 +11088,8 @@ show_capslock_feedback (GtkEntry    *entry,
 {
   GtkEntryPrivate *priv = entry->priv;
 
-  if (gtk_entry_get_icon_storage_type (entry, GTK_ENTRY_ICON_SECONDARY) == GTK_IMAGE_EMPTY)
+  if (gtk_entry_get_icon_storage_type (entry, GTK_ENTRY_ICON_SECONDARY) == GTK_IMAGE_EMPTY ||
+      priv->password_indicator)
     {
       gtk_entry_set_icon_from_icon_name (entry, GTK_ENTRY_ICON_SECONDARY, "dialog-warning-symbolic");
       gtk_entry_set_icon_activatable (entry, GTK_ENTRY_ICON_SECONDARY, FALSE);
@@ -10999,8 +11109,8 @@ remove_capslock_feedback (GtkEntry *entry)
 
   if (priv->caps_lock_warning_shown)
     {
-      gtk_entry_set_icon_from_icon_name (entry, GTK_ENTRY_ICON_SECONDARY, NULL);
       priv->caps_lock_warning_shown = FALSE;
+      update_password_indicator (entry);
     } 
 }
 

tests/testentryicons.c

@@ -214,13 +214,7 @@ main (int argc, char **argv)
   gtk_grid_attach (GTK_GRID (grid), entry, 1, 3, 1, 1);
   gtk_entry_set_visibility (GTK_ENTRY (entry), FALSE);
 
-  gtk_entry_set_icon_from_icon_name (GTK_ENTRY (entry),
+  g_object_set (entry, "password-indicator", TRUE, NULL);
-                                     GTK_ENTRY_ICON_PRIMARY,
-                                     "dialog-password-symbolic");
-
-  gtk_entry_set_icon_activatable (GTK_ENTRY (entry),
-				  GTK_ENTRY_ICON_PRIMARY,
-				  FALSE);
 
   /* Name - Does not set any icons. */
   label = gtk_label_new ("Name:");