Track skipping using Volume Up-Down Buttons - Revision history

FXDemolisher: /* Procedure */

2009-07-24T12:37:02Z

Procedure

FXDemolisher: /* Procedure */

2009-07-24T12:34:42Z

Procedure

Hopspitfire: Track-skipping-using-volume-up-down-buttons moved to Track skipping using Volume Up-Down Buttons: Retain naming convention.

2009-07-22T17:18:55Z

Track-skipping-using-volume-up-down-buttons moved to Track skipping using Volume Up-Down Buttons: Retain naming convention.

Noir: New page: == Preamble == You will need write permissions to the filesystem on your pre to apply this patch. To get write persmissions execute: rootfs_open -w To re...

2009-07-21T01:35:27Z

New page: == Preamble == You will need write permissions to the filesystem on your pre to apply this patch. To get write persmissions execute: <source lang="text"> rootfs_open -w </source> To re...

New page

== Preamble ==

You will need write permissions to the filesystem on your pre to apply this patch.

To get write persmissions execute:

<source lang="text">
rootfs_open -w
</source>

To remount the filesystem as read-only:

<source lang="text">
mount -o remount,ro /
</source>

== Motivation ==

A headset with in-lined track skip buttons is nice, but when you're using headphones not created for a phone, or you're in a car with the phone connected to the vehicle's sound system, it's nice to be able to skip to the next or previous track with a simple button press. The Blackberry Curve ([[user FXDemolisher]]'s old phone) had this ability by holding down the volume up/down buttons for a second or so. The track would skip and the volume would be restored to normal. This patch aims to add the same functionality to the Pre.

== Procedure ==

This is one long patch that adds several sections to the following file:
<source lang="text">
/usr/palm/applications/com.palm.app.musicplayer/app/controllers/localnowplaying-assistant.js
</source>

##red|Please back up this file before trying this patch.##

<source lang="text">
--- localnowplaying-assistant.js_2009-06-28 Sun Jun 28 17:02:12 2009
+++ localnowplaying-assistant.js Sun Jun 28 19:28:29 2009 +++
@@ -21,6 +21,15 @@
if (title)
this.title = title;

+ '' volume key track skip tracking vars
+ this.currentVolume = -1;
+ this.currentVolumeScenario = undefined;
+ this.currentVolumeSubscription = undefined;
+ this.volumeKeySubscription = undefined;
+ this.volumeKeyDownVolume = -1;
+ this.volumeKeyDownScenario = undefined;
+ this.volumeKeySkipTo = 'none';
+ this.volumeKeySkipTimer = undefined;
},

setup: function() {
@@ -114,14 +123,101 @@
AppAssistant.addActiveScene (this);
this.refreshAppMenu();

+ '' subscribe to volume key events
+ this.volumeKeySubscription = new Mojo.Service.Request(
+ 'palm:''com.palm.keys/audio',
+ {
+ method: 'status',
+ parameters: {'subscribe': true},
+ onFailure: function() { Mojo.Log.error("Could not subscribe to volume key events"); },
+ onSuccess: this.handleVolumeKeys.bind(this),
+ });
+
+ '' subscribe to audio events - know what current volume is
+ this.currentVolumeSubscription = new Mojo.Service.Request(
+ 'palm:''com.palm.audio/media',
+ {
+ method: 'status',
+ parameters: {'subscribe': true},
+ onFailure: function() { Mojo.Log.error("could not subscribe to volume change events"); },
+ onSuccess: this.handleMediaNotifications.bind(this),
+ });
+
},

stopDragHandler: function(dragEvent) {
dragEvent.stop();
},

-
-
+ '' handlers for the volume keys, used to skip tracks
+ handleVolumeKeys: function(payload) {
+ '' down state, record direction if needed and set timer to skip the track
+ if(payload.state === 'down') {
+ '' ignore any presses if we are already tracking a down state
+ if(this.volumeKeySkipTo != 'none') { return; }
+
+ if(payload.key === 'volume_up') { this.volumeKeySkipTo = 'next'; }
+ else if (payload.key === 'volume_down') { this.volumeKeySkipTo = 'prev'; }
+
+ '' track the volume when the user pressed the key so that we can return to it
+ this.volumeKeyDownVolume = this.currentVolume;
+ this.volumeKeyDownScenario = this.currentScenario;
+
+ '' schedule the check to skip the track
+ this.volumeKeySkipTimer = this.controller.window.setTimeout(this.checkVolumeKeySkip.bind(this), 1200);
+ }
+
+ '' up state, clear tracking variables
+ else {
+ this.volumeKeySkipTo = 'none';
+ this.volumeOnLastVolumeKeyPress = -1;
+ this.volumeKeyDownVolume = -1;
+ this.volumeKeyDownScenario = undefined;
+
+ if(this.volumeKeySkipTimer) {
+ this.controller.window.clearTimeout(this.volumeKeySkipTimer);
+ this.volumeKeySkipTimer = undefined;
+ }
+ }
+ },
+
+ '' check if we need to skip to next/prev track due to user holding down volume keys
+ checkVolumeKeySkip: function() {
+ if(this.volumeKeySkipTo === 'next') { this.nextSong(); }
+ else if (this.volumeKeySkipTo === 'prev') { this.prevSong(true); }
+
+ this.volumeKeySkipTo = 'none';
+
+ '' set up volume restore in after some time,
+ '' so that user has time to let go of the button
+ setTimeout("assistant.restoreVolume('" + this.volumeKeyDownScenario + "', " + this.volumeKeyDownVolume +")", 1000);
+ },
+
+ '' restore volume to the given scenario and level
+ restoreVolume: function (scenario, volume) {
+
+ '' restore volume to the one when the user held down the button
+ if(volume >= 0) {
+ new Mojo.Service.Request('palm:''com.palm.audio/media',
+ {
+ method: 'setVolume',
+ parameters: {scenario: scenario, volume: volume},
+ onFailure: function() { Mojo.Log.error("Could not restore volume"); }
+ });
+ }
+ },
+
+ '' record current volume each time it changes
+ handleMediaNotifications: function(payload) {
+ if(!payload) { return; }
+
+ if(payload.action == 'changed' && payload.changed.length == 1 && (payload.changed.indexOf('volume') != -1)) {
+ this.currentVolume = payload.volume;
+ this.currentScenario = payload.scenario;
+ }
+ },
+
+
handleFlick: function(event){
event.stop();

@@ -760,7 +856,15 @@

AppAssistant.removeActiveScene(this);

-
+ '' clean up subscription to volume keys
+ if(this.volumeKeySubscription) {
+ this.volumeKeySubscription.cancel();
+ }
+
+ '' clean up subscription to volume level
+ if(this.currentVolumeSubscription) {
+ this.currentVolumeSubscription.cancel();
+ }
},

deactivate: function(){
</source>

== Notes ==

==== Track skip at start up issue ====
The first volume up/down press in the app causes the track to skip. I am not sure why, it may have to do with the amount of time it takes for the bar assistant to come up and does not give enough time for the volume key up event to propagate. ~ FXDemolisher

==== Timeouts ====
There are two main timeout values in the code. One controls the amount of time the button has to be held down to skip:
<source lang="text">
this.volumeKeySkipTimer = this.controller.window.setTimeout(this.checkVolumeKeySkip.bind(this), 1200);
</source>
The other controls the amount of time the user has to lift the finger off the key before the volume is restored to normal:
<source lang="text">
setTimeout("assistant.restoreVolume('" + this.volumeKeyDownScenario + "', " + this.volumeKeyDownVolume +")", 1000);
</source>

I kept the skip timeout at 1200 so that the volume doesn't have enough time to go too high when you are wearing headphones but is not short enough to cause random skips. The restore timeout is at 1000 and seems to work fine. If you shorten the second timeout the volume may not restore right since the user is still pressing the button when the setVolume call is made.

~ FXDemolisher

@@ Line 26: / Line 26: @@
 </source>
-##red|Please back up this file before trying this patch.##
+*Please back up this file before trying this patch.
 <source lang="text">

@@ Line 35: / Line 35: @@
   				this.title = title;
-+			'' volume key track skip tracking vars
++			// volume key track skip tracking vars
 +			this.currentVolume = -1;
 +			this.currentVolumeScenario = undefined;
@@ Line 51: / Line 51: @@
   			this.refreshAppMenu();
-+			'' subscribe to volume key events
++			// subscribe to volume key events
 +			this.volumeKeySubscription = new Mojo.Service.Request(
-+				'palm:''com.palm.keys/audio',
++				'palm://com.palm.keys/audio',
 +				{
 +					method: 'status',
@@ Line 61: / Line 61: @@
 +				});
++
-+			'' subscribe to audio events - know what current volume is
++			// subscribe to audio events - know what current volume is
 +			this.currentVolumeSubscription = new Mojo.Service.Request(
-+				'palm:''com.palm.audio/media',
++				'palm://com.palm.audio/media',
 +				{
 +					method: 'status',
@@ Line 79: / Line 79: @@
+-
+-
-+    		'' handlers for the volume keys, used to skip tracks
++    		// handlers for the volume keys, used to skip tracks
 +		handleVolumeKeys: function(payload) {
-+			'' down state, record direction if needed and set timer to skip the track
++			// down state, record direction if needed and set timer to skip the track
 +			if(payload.state === 'down') {
-+				'' ignore any presses if we are already tracking a down state
++				// ignore any presses if we are already tracking a down state
 +			        if(this.volumeKeySkipTo != 'none') { return; }
++
@@ Line 89: / Line 89: @@
 +				else if (payload.key === 'volume_down') { this.volumeKeySkipTo = 'prev'; }
++
-+				'' track the volume when the user pressed the key so that we can return to it
++				// track the volume when the user pressed the key so that we can return to it
 +				this.volumeKeyDownVolume = this.currentVolume;
 +				this.volumeKeyDownScenario = this.currentScenario;
++
-+				'' schedule the check to skip the track
++				// schedule the check to skip the track
 +				this.volumeKeySkipTimer = this.controller.window.setTimeout(this.checkVolumeKeySkip.bind(this), 1200);
 +			}
++
-+			'' up state, clear tracking variables
++			// up state, clear tracking variables
 +			else {
 +				this.volumeKeySkipTo = 'none';
@@ Line 111: / Line 111: @@
 +		},
++
-+		'' check if we need to skip to next/prev track due to user holding down volume keys
++		// check if we need to skip to next/prev track due to user holding down volume keys
 +		checkVolumeKeySkip: function() {
 +			if(this.volumeKeySkipTo === 'next') { this.nextSong(); }
@@ Line 118: / Line 118: @@
 +			this.volumeKeySkipTo = 'none';
++
-+			'' set up volume restore in after some time,
++			// set up volume restore in after some time,
-+			'' so that user has time to let go of the button
++			// so that user has time to let go of the button
 +			setTimeout("assistant.restoreVolume('" + this.volumeKeyDownScenario + "', " + this.volumeKeyDownVolume +")", 1000);
 +		},
++
-+		'' restore volume to the given scenario and level
++		// restore volume to the given scenario and level
 +		restoreVolume: function (scenario, volume) {
++
-+			'' restore volume to the one when the user held down the button
++			// restore volume to the one when the user held down the button
 +			if(volume >= 0) {
-+				new Mojo.Service.Request('palm:''com.palm.audio/media',
++				new Mojo.Service.Request('palm://com.palm.audio/media',
 +					{
 +						method: 'setVolume',
@@ Line 137: / Line 137: @@
 +		},
++
-+		'' record current volume each time it changes
++		// record current volume each time it changes
 +		handleMediaNotifications: function(payload) {
 +			if(!payload) { return; }
@@ Line 156: / Line 156: @@
+-
-+			'' clean up subscription to volume keys
++			// clean up subscription to volume keys
 +			if(this.volumeKeySubscription) {
 +				this.volumeKeySubscription.cancel();
 +			}
++
-+			'' clean up subscription to volume level
++			// clean up subscription to volume level
 +			if(this.currentVolumeSubscription) {
 +				this.currentVolumeSubscription.cancel();

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