[gnome-shell/wip/carlosg/fix-issue-46: 4/8] keyboard: Shift key shouldn't latch the state unless long pressed

[Carlos Garnacho <carlosg src gnome org>]

commit 5f6745cad026e6c57d84fad0cb735f84891aaf6f
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu Feb 15 12:20:51 2018 +0100

    keyboard: Shift key shouldn't latch the state unless long pressed
    
    Instead of latching all states, make shift unlatched by default, and only
    latched when making a long press on the key. When not latched, the keyboard
    will switch to the first level (alphabetic lowercase) after the first key
    press.
    
    Also, move the actual level switch to Key::pressed, so it feels more
    reactive on long press.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/issues/46

 js/ui/keyboard.js | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)
---
diff --git a/js/ui/keyboard.js b/js/ui/keyboard.js
index ea66b8375..37e86fdb7 100644
--- a/js/ui/keyboard.js
+++ b/js/ui/keyboard.js
@@ -499,6 +499,7 @@ var Keyboard = new Lang.Class({
 
         this._enableKeyboard = false; // a11y settings value
         this._enabled = false; // enabled state (by setting or device type)
+        this._latched = false; // current level is latched
 
         this._a11yApplicationsSettings = new Gio.Settings({ schema_id: A11Y_APPLICATIONS_SCHEMA });
         this._a11yApplicationsSettings.connect('changed', Lang.bind(this, this._syncEnabled));
@@ -787,6 +788,9 @@ var Keyboard = new Lang.Class({
                         this._keyboardController.keyvalRelease(keyval);
                     button._keyvalPress = false;
                 }
+
+                if (!this._latched)
+                    this._setActiveLayer(0);
             }));
 
             layout.appendKey(button.actor, button.keyButton.keyWidth);
@@ -821,13 +825,16 @@ var Keyboard = new Lang.Class({
             let actor = extraButton.keyButton;
 
             extraButton.connect('pressed', Lang.bind(this, function() {
-                if (keyval != null)
+                if (switchToLevel != null) {
+                    this._setActiveLayer(switchToLevel);
+                    // Shift only gets latched on long press
+                    this._latched = (switchToLevel != 1);
+                } else if (keyval != null) {
                     this._keyboardController.keyvalPress(keyval);
+                }
             }));
             extraButton.connect('released', Lang.bind(this, function() {
-                if (switchToLevel != null)
-                    this._setActiveLayer(switchToLevel);
-                else if (keyval != null)
+                if (keyval != null)
                     this._keyboardController.keyvalRelease(keyval);
                 else if (action == 'hide')
                     this.hide();
@@ -835,6 +842,12 @@ var Keyboard = new Lang.Class({
                     this._popupLanguageMenu(actor);
             }));
 
+            if (switchToLevel == 1) {
+                extraButton.connect('long-press', Lang.bind(this, function() {
+                    this._latched = true;
+                }));
+            }
+
             /* Fixup default keys based on the number of levels/keys */
             if (key.label == '⇧' && numLevels == 3) {
                 if (key.right) {