Fix brightness applet scroll

Author: balazs-endresz

applets/brightness/brightness-applet.c

@@ -115,6 +115,13 @@ static void      gpm_applet_destroy_cb            (GtkWidget *widget);
  * too long one will seem unresponsive. */
 #define GPM_BRIGHTNESS_APPLET_SLIDER_FREQUENCY	100
 
+/* Brightness percentage changes for each input method */
+#define GPM_BRIGHTNESS_APPLET_PERCENT_CHANGE_BUTTON 1  /* plus/minus buttons in the popup */
+#define GPM_BRIGHTNESS_APPLET_PERCENT_CHANGE_ARROW 1  /* arrow keys when the popup is open */
+#define GPM_BRIGHTNESS_APPLET_PERCENT_CHANGE_SCROLL 5  /* scrolling over the indicator icon */
+#define GPM_BRIGHTNESS_APPLET_PERCENT_CHANGE_PAGE 10  /* page up/down keys when the popup is open */
+
+
 /**
  * gpm_applet_get_brightness:
  * Return value: Success value, or zero for failure
@@ -403,6 +410,26 @@ gpm_applet_update_popup_level (GpmBrightnessApplet *applet)
 	gpm_applet_update_tooltip (applet);
 }
 
+/**
+ * gpm_applet_adjust_brightness:
+ * @applet: Brightness applet instance
+ *
+ * Change brightness by a given percentage and keep the slider value in sync.
+ **/
+static void
+gpm_applet_adjust_brightness (GpmBrightnessApplet *applet, int percent)
+{
+	if (applet->level == -1) {
+		return;
+	}
+	if (percent > 0) {
+		applet->level = applet->level <= (100 - percent) ? applet->level + percent : 100;
+	} else {
+		applet->level = applet->level >= -percent ? applet->level + percent : 0;
+	}
+	gtk_range_set_value (GTK_RANGE(applet->slider), applet->level);
+}
+
 /**
  * gpm_applet_plus_cb:
  * @widget: The sending widget (plus button)
@@ -413,11 +440,7 @@ gpm_applet_update_popup_level (GpmBrightnessApplet *applet)
 static gboolean
 gpm_applet_plus_cb (GtkWidget *w, GpmBrightnessApplet *applet)
 {
-	if (applet->level < 100) {
-		applet->level++;
-	}
-	applet->call_worked = gpm_applet_set_brightness (applet);
-	gpm_applet_update_popup_level (applet);
+	gpm_applet_adjust_brightness (applet, GPM_BRIGHTNESS_APPLET_PERCENT_CHANGE_BUTTON);
 	return TRUE;
 }
 
@@ -431,11 +454,7 @@ gpm_applet_plus_cb (GtkWidget *w, GpmBrightnessApplet *applet)
 static gboolean
 gpm_applet_minus_cb (GtkWidget *w, GpmBrightnessApplet *applet)
 {
-	if (applet->level > 0) {
-		applet->level--;
-	}
-	applet->call_worked = gpm_applet_set_brightness (applet);
-	gpm_applet_update_popup_level (applet);
+	gpm_applet_adjust_brightness (applet, -GPM_BRIGHTNESS_APPLET_PERCENT_CHANGE_BUTTON);
 	return TRUE;
 }
 
@@ -487,8 +506,6 @@ gpm_applet_slide_cb (GtkWidget *w, GpmBrightnessApplet *applet)
 static gboolean
 gpm_applet_key_press_cb (GtkWidget *popup, GdkEventKey *event, GpmBrightnessApplet *applet)
 {
-	int i;
-
 	switch (event->keyval) {
 	case GDK_KEY_KP_Enter:
 	case GDK_KEY_ISO_Enter:
@@ -508,25 +525,21 @@ gpm_applet_key_press_cb (GtkWidget *popup, GdkEventKey *event, GpmBrightnessAppl
 		}
 		break;
 	case GDK_KEY_Page_Up:
-		for (i = 0;i < 10;i++) {
-			gpm_applet_plus_cb (NULL, applet);
-		}
+		gpm_applet_adjust_brightness (applet, GPM_BRIGHTNESS_APPLET_PERCENT_CHANGE_PAGE);
 		return TRUE;
 		break;
 	case GDK_KEY_Left:
 	case GDK_KEY_Up:
-		gpm_applet_plus_cb (NULL, applet);
+		gpm_applet_adjust_brightness (applet, GPM_BRIGHTNESS_APPLET_PERCENT_CHANGE_ARROW);
 		return TRUE;
 		break;
 	case GDK_KEY_Page_Down:
-		for (i = 0;i < 10;i++) {
-			gpm_applet_minus_cb (NULL, applet);
-		}
+		gpm_applet_adjust_brightness (applet, -GPM_BRIGHTNESS_APPLET_PERCENT_CHANGE_PAGE);
 		return TRUE;
 		break;
 	case GDK_KEY_Right:
 	case GDK_KEY_Down:
-		gpm_applet_minus_cb (NULL, applet);
+		gpm_applet_adjust_brightness (applet, -GPM_BRIGHTNESS_APPLET_PERCENT_CHANGE_ARROW);
 		return TRUE;
 		break;
 	default:
@@ -549,18 +562,11 @@ gpm_applet_key_press_cb (GtkWidget *popup, GdkEventKey *event, GpmBrightnessAppl
 static gboolean
 gpm_applet_scroll_cb (GpmBrightnessApplet *applet, GdkEventScroll *event)
 {
-	int i;
-
 	if (event->type == GDK_SCROLL) {
 		if (event->direction == GDK_SCROLL_UP) {
-			for (i = 0;i < 5;i++) {
-				gpm_applet_plus_cb (NULL, applet);
-			}
-
+			gpm_applet_adjust_brightness (applet, GPM_BRIGHTNESS_APPLET_PERCENT_CHANGE_SCROLL);
 		} else {
-			for (i = 0;i < 5;i++) {
-				gpm_applet_minus_cb (NULL, applet);
-			}
+			gpm_applet_adjust_brightness (applet, -GPM_BRIGHTNESS_APPLET_PERCENT_CHANGE_SCROLL);
 		}
 		return TRUE;
 	}
@@ -710,7 +716,7 @@ gpm_applet_popup_cb (GpmBrightnessApplet *applet, GdkEventButton *event)
 	/* otherwise pop */
 	applet->popped = TRUE;
 
-	/* create a new popup (initial or if panel parameters changed) */
+	/* create a new popup (if panel parameters changed) */
 	if (applet->popup == NULL) {
 		gpm_applet_create_popup (applet);
 	}
@@ -1026,6 +1032,10 @@ gpm_brightness_applet_init (GpmBrightnessApplet *applet)
 	mate_panel_applet_set_flags (MATE_PANEL_APPLET (applet), MATE_PANEL_APPLET_EXPAND_MINOR);
 	gtk_widget_set_events (GTK_WIDGET (applet), GDK_SCROLL_MASK);
 
+	/* Create popup (slider) upfront, so that we can keep it
+	 * up to date from scroll events before it's ever opened. */
+	gpm_applet_create_popup (applet);
+
 	/* show */
 	gtk_widget_show_all (GTK_WIDGET(applet));