[gnome-games/wip/aplazas/gamepad-navigation: 3/7] Add GamepadBrowse

[Adrien Plazas <aplazas src gnome org>]

commit 398b7164c2952b24b5967bc5d8392036ecd1af50
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Sun Aug 5 10:16:52 2018 +0200

    Add GamepadBrowse
    
    This gesture-like object parses gamepad events and emit browsing-related
    signals. This is based on the code from CollectionIconView, it will
    replace it while making it usable in other places.

 src/meson.build            |   1 +
 src/ui/gamepad-browse.vala | 174 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 175 insertions(+)
---
diff --git a/src/meson.build b/src/meson.build
index db93de81..493b0d81 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -135,6 +135,7 @@ vala_sources = [
   'ui/empty-collection.vala',
   'ui/error-display.vala',
   'ui/error-info-bar.vala',
+  'ui/gamepad-browse.vala',
   'ui/gamepad-configurer.vala',
   'ui/gamepad-mapper.vala',
   'ui/gamepad-tester.vala',
diff --git a/src/ui/gamepad-browse.vala b/src/ui/gamepad-browse.vala
new file mode 100644
index 00000000..3079589f
--- /dev/null
+++ b/src/ui/gamepad-browse.vala
@@ -0,0 +1,174 @@
+// This file is part of GNOME Games. License: GPL-3.0+.
+
+private class Games.GamepadBrowse : Object {
+       private enum CursorMovementSource {
+               UNKNOWN,
+               DIRECTIONAL_PAD,
+               ANALOG_STICK,
+       }
+
+       private const double DEAD_ZONE = 0.3;
+
+       public signal bool browse (Gtk.DirectionType direction);
+       public signal bool accept ();
+       public signal bool cancel ();
+
+       private Gtk.DirectionType cursor_direction;
+       private CursorMovementSource cursor_movement_source;
+       private Manette.Device? cursor_movement_device;
+       private double cursor_speed;
+       private uint cursor_timeout;
+
+       public bool gamepad_button_press_event (Manette.Event event) {
+               uint16 button;
+               if (!event.get_button (out button))
+                       return false;
+
+               switch (button) {
+               case EventCode.BTN_A:
+                       return accept ();
+               case EventCode.BTN_B:
+                       return cancel ();
+               case EventCode.BTN_START:
+                       return accept ();
+               case EventCode.BTN_DPAD_UP:
+                       return move_cursor (Gtk.DirectionType.UP, CursorMovementSource.DIRECTIONAL_PAD, 
event.get_device (), 1.0);
+               case EventCode.BTN_DPAD_DOWN:
+                       return move_cursor (Gtk.DirectionType.DOWN, CursorMovementSource.DIRECTIONAL_PAD, 
event.get_device (), 1.0);
+               case EventCode.BTN_DPAD_LEFT:
+                       return move_cursor (Gtk.DirectionType.LEFT, CursorMovementSource.DIRECTIONAL_PAD, 
event.get_device (), 1.0);
+               case EventCode.BTN_DPAD_RIGHT:
+                       return move_cursor (Gtk.DirectionType.RIGHT, CursorMovementSource.DIRECTIONAL_PAD, 
event.get_device (), 1.0);
+               default:
+                       return false;
+               }
+       }
+
+       public bool gamepad_button_release_event (Manette.Event event) {
+               uint16 button;
+               if (!event.get_button (out button))
+                       return false;
+
+               switch (button) {
+               case EventCode.BTN_DPAD_UP:
+                       if (cursor_movement_source != CursorMovementSource.DIRECTIONAL_PAD ||
+                           cursor_movement_device != event.get_device ())
+                               return false;
+
+                       return cancel_cursor_movement_for_direction (Gtk.DirectionType.UP);
+               case EventCode.BTN_DPAD_DOWN:
+                       if (cursor_movement_source != CursorMovementSource.DIRECTIONAL_PAD ||
+                           cursor_movement_device != event.get_device ())
+                               return false;
+
+                       return cancel_cursor_movement_for_direction (Gtk.DirectionType.DOWN);
+               case EventCode.BTN_DPAD_LEFT:
+                       if (cursor_movement_source != CursorMovementSource.DIRECTIONAL_PAD ||
+                           cursor_movement_device != event.get_device ())
+                               return false;
+
+                       return cancel_cursor_movement_for_direction (Gtk.DirectionType.LEFT);
+               case EventCode.BTN_DPAD_RIGHT:
+                       if (cursor_movement_source != CursorMovementSource.DIRECTIONAL_PAD ||
+                           cursor_movement_device != event.get_device ())
+                               return false;
+
+                       return cancel_cursor_movement_for_direction (Gtk.DirectionType.RIGHT);
+               default:
+                       return false;
+               }
+       }
+
+       public bool gamepad_absolute_axis_event (Manette.Event event) {
+               uint16 axis;
+               double value;
+               if (!event.get_absolute (out axis, out value))
+                       return false;
+
+               // We square the value to get the speed so the progression is
+               // exponential. No need to compute the absolute value if we square it.
+               switch (axis) {
+               case EventCode.ABS_X:
+                       if (value > DEAD_ZONE)
+                               return move_cursor (Gtk.DirectionType.RIGHT, 
CursorMovementSource.ANALOG_STICK, event.get_device (), value * value);
+                       else if (value < -DEAD_ZONE)
+                               return move_cursor (Gtk.DirectionType.LEFT, 
CursorMovementSource.ANALOG_STICK, event.get_device (), value * value);
+                       else if (cursor_movement_source == CursorMovementSource.ANALOG_STICK &&
+                                cursor_movement_device == event.get_device () &&
+                                (cursor_direction == Gtk.DirectionType.LEFT || cursor_direction == 
Gtk.DirectionType.RIGHT))
+                               cancel_cursor_movement ();
+
+                       return false;
+               case EventCode.ABS_Y:
+                       if (value > DEAD_ZONE)
+                               return move_cursor (Gtk.DirectionType.DOWN, 
CursorMovementSource.ANALOG_STICK, event.get_device (), value * value);
+                       else if (value < -DEAD_ZONE)
+                               return move_cursor (Gtk.DirectionType.UP, CursorMovementSource.ANALOG_STICK, 
event.get_device (), value * value);
+                       else if (cursor_movement_source == CursorMovementSource.ANALOG_STICK &&
+                                cursor_movement_device == event.get_device () &&
+                                (cursor_direction == Gtk.DirectionType.UP || cursor_direction == 
Gtk.DirectionType.DOWN))
+                               cancel_cursor_movement ();
+
+                       return false;
+               default:
+                       return false;
+               }
+       }
+
+       private bool move_cursor (Gtk.DirectionType direction, CursorMovementSource source, Manette.Device 
device, double speed) {
+               cursor_movement_source = source;
+               cursor_movement_device = device;
+               cursor_speed = speed;
+
+               if (cursor_timeout != 0 && cursor_direction == direction)
+                       return true;
+
+               if (cursor_timeout != 0)
+                       Source.remove (cursor_timeout);
+
+               cursor_timeout = 0;
+               cursor_direction = direction;
+
+               if (!browse (cursor_direction))
+                       return false;
+
+               cursor_timeout = Timeout.add (500, setup_cursor_cb);
+
+               return true;
+       }
+
+       private bool setup_cursor_cb () {
+               if (cursor_speed == 0) {
+                       cancel_cursor_movement ();
+
+                       return false;
+               }
+
+               if (!browse (cursor_direction))
+                       return false;
+
+               cursor_timeout = Timeout.add ((uint) (30 / cursor_speed), setup_cursor_cb);
+
+               return false;
+       }
+
+       public void cancel_cursor_movement () {
+               if (cursor_timeout != 0)
+                       Source.remove (cursor_timeout);
+
+               cursor_movement_source = CursorMovementSource.UNKNOWN;
+               cursor_movement_device = null;
+               cursor_timeout = 0;
+
+               return;
+       }
+
+       private bool cancel_cursor_movement_for_direction (Gtk.DirectionType direction) {
+               if (cursor_direction != direction)
+                       return false;
+
+               cancel_cursor_movement ();
+
+               return true;
+       }
+}