Change volume when scrolling on the indicator

This depends on a new root menu property: x-canonical-scroll-action. It points
to an action that gets activated whenever the user scrolls the mouse over the
indicator. The parameter of that action signifies the magnitude and direction
of the scroll.

2 files changed, 15 insertions, 0 deletions

diff --git a/src/service.vala b/src/service.vala
index 4d64502..0651c0e 100644
--- a/src/service.vala
+++ b/src/service.vala
@@ -64,6 +64,7 @@ public class IndicatorSound.Service {
 
 	const ActionEntry[] action_entries = {
 		{ "root", null, null, "@a{sv} {}", null },
+		{ "scroll", activate_scroll_action, "i", null, null },
 		{ "desktop-settings", activate_desktop_settings, null, null, null },
 		{ "phone-settings", activate_phone_settings, null, null, null },
 	};
@@ -76,6 +77,19 @@ public class IndicatorSound.Service {
 	MediaPlayerList players;
 	uint player_action_update_id;
 
+	void activate_scroll_action (SimpleAction action, Variant? param) {
+		const double volume_step_percentage = 0.06;
+		int delta = param.get_int32(); /* positive for up, negative for down */
+
+		double v = this.volume_control.get_volume () + volume_step_percentage * delta;
+		if (v > 1.0)
+			v = 1.0;
+		else if (v < 0.0)
+			v = 0.0;
+
+		this.volume_control.set_volume (v);
+	}
+
 	void activate_desktop_settings (SimpleAction action, Variant? param) {
 		var env = Environment.get_variable ("DESKTOP_SESSION");
 		string cmd;
diff --git a/src/sound-menu.vala b/src/sound-menu.vala
index 415a5be..7ac8930 100644
--- a/src/sound-menu.vala
+++ b/src/sound-menu.vala
@@ -40,6 +40,7 @@ class SoundMenu: Object
 
 		var root_item = new MenuItem (null, "indicator.root");
 		root_item.set_attribute ("x-canonical-type", "s", "com.canonical.indicator.root");
+		root_item.set_attribute ("x-canonical-scroll-action", "s", "indicator.scroll");
 		root_item.set_submenu (this.menu);
 
 		this.root = new Menu ();