From 4ac79e422129e654e48909017a50b066b2f587d1 Mon Sep 17 00:00:00 2001
From: pacien
Date: Fri, 24 Aug 2018 01:39:40 +0200
Subject: Handle click and touch events

---
 pointless/viewer/stage/actions.js | 121 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 pointless/viewer/stage/actions.js

(limited to 'pointless/viewer/stage/actions.js')

diff --git a/pointless/viewer/stage/actions.js b/pointless/viewer/stage/actions.js
new file mode 100644
index 0000000..271d7b7
--- /dev/null
+++ b/pointless/viewer/stage/actions.js
@@ -0,0 +1,121 @@
+/*
+ * Pointless Viewer, a web-based Beamer presentation viewer
+ * Copyright (C) 2018 Pacien TRAN-GIRARD
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+"use strict";
+
+class ActionEventHandler {
+  constructor(onNext, onPrevious) {
+    this.onNext = onNext;
+    this.onPrevious = onPrevious;
+  }
+}
+
+class KeyboardEventHandler extends ActionEventHandler {
+  register(window) {
+    const self = this;
+    window.addEventListener("keydown", function(event) {
+      self._onCommand(event);
+    })
+  }
+
+  _onCommand(keyboardEvent) {
+    switch (keyboardEvent.key) {
+      case "Enter":
+      case " ":
+      case "ArrowRight":
+      case "n":
+        return this.onNext();
+
+      case "ArrowLeft":
+      case "p":
+        return this.onPrevious();
+    }
+  }
+}
+
+class MouseClickEventHandler extends ActionEventHandler {
+  register(window) {
+    const self = this;
+    window.addEventListener("click", function(event) {
+      self._onCommand(event);
+    })
+  }
+
+  _onCommand(mouseEvent) {
+    this.onNext();
+  }
+}
+
+class TouchSwipeEventHandler extends ActionEventHandler {
+  constructor(onNext, onPrevious) {
+    super(onNext, onPrevious);
+    this.touchStartEvent = null;
+    this.touchMoveEvent = null;
+  }
+
+  register(window) {
+    const self = this;
+
+    window.addEventListener("touchstart", function(event) {
+      event.preventDefault();
+      self._onTouchStart(event);
+    });
+
+    window.addEventListener("touchmove", function(event) {
+      event.preventDefault();
+      self._onTouchMove(event);
+    });
+
+    window.addEventListener("touchend", function(event) {
+      event.preventDefault();
+      self._onTouchEnd();
+    });
+
+    window.addEventListener("touchcancel", function(event) {
+      event.preventDefault();
+    });
+  }
+
+  _onTouchStart(touchEvent) {
+    this.touchStartEvent = touchEvent;
+  }
+
+  _onTouchMove(touchEvent) {
+    this.touchMoveEvent = touchEvent;
+  }
+
+  _onTouchEnd() {
+    if (this.touchStartEvent == null || this.touchMoveEvent == null) return;
+
+    const touchDown = this._xCoordinate(this.touchStartEvent);
+    const touchUp = this._xCoordinate(this.touchMoveEvent);
+    const xDelta = touchDown - touchUp;
+
+    if (xDelta > 0)
+      this.onNext();
+    else if (xDelta < 0)
+      this.onPrevious();
+    
+    this.touchStartEvent = null;
+    this.touchMoveEvent = null;
+  }
+
+  _xCoordinate(touchEvent) {
+    return touchEvent.touches[0].clientX; // first finger
+  }
+}
-- 
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