1 files changed, 94 insertions, 0 deletions
diff --git a/ui/static/js/touch_handler.js b/ui/static/js/touch_handler.js
new file mode 100644
index 00000000..69488a50
--- /dev/null
+++ b/ui/static/js/touch_handler.js
@@ -0,0 +1,94 @@
+class TouchHandler {
+    constructor() {
+        this.reset();
+    }
+
+    reset() {
+        this.touch = {
+            start: {x: -1, y: -1},
+            move: {x: -1, y: -1},
+            element: null
+        };
+    }
+
+    calculateDistance() {
+        if (this.touch.start.x >= -1 && this.touch.move.x >= -1) {
+            let horizontalDistance = Math.abs(this.touch.move.x - this.touch.start.x);
+            let verticalDistance = Math.abs(this.touch.move.y - this.touch.start.y);
+
+            if (horizontalDistance > 30 && verticalDistance < 70) {
+                return this.touch.move.x - this.touch.start.x;
+            }
+        }
+
+        return 0;
+    }
+
+    findElement(element) {
+        if (element.classList.contains("touch-item")) {
+            return element;
+        }
+
+        return DomHelper.findParent(element, "touch-item");
+    }
+
+    onTouchStart(event) {
+        if (event.touches === undefined || event.touches.length !== 1) {
+            return;
+        }
+
+        this.reset();
+        this.touch.start.x = event.touches[0].clientX;
+        this.touch.start.y = event.touches[0].clientY;
+        this.touch.element = this.findElement(event.touches[0].target);
+    }
+
+    onTouchMove(event) {
+        if (event.touches === undefined || event.touches.length !== 1 || this.element === null) {
+            return;
+        }
+
+        this.touch.move.x = event.touches[0].clientX;
+        this.touch.move.y = event.touches[0].clientY;
+
+        let distance = this.calculateDistance();
+        let absDistance = Math.abs(distance);
+
+        if (absDistance > 0) {
+            let opacity = 1 - (absDistance > 75 ? 0.9 : absDistance / 75 * 0.9);
+            let tx = distance > 75 ? 75 : (distance < -75 ? -75 : distance);
+
+            this.touch.element.style.opacity = opacity;
+            this.touch.element.style.transform = "translateX(" + tx + "px)";
+        }
+    }
+
+    onTouchEnd(event) {
+        if (event.touches === undefined) {
+            return;
+        }
+
+        if (this.touch.element !== null) {
+            let distance = Math.abs(this.calculateDistance());
+
+            if (distance > 75) {
+                EntryHandler.toggleEntryStatus(this.touch.element);
+            }
+            this.touch.element.style.opacity = 1;
+            this.touch.element.style.transform = "none";
+        }
+
+        this.reset();
+    }
+
+    listen() {
+        let elements = document.querySelectorAll(".touch-item");
+
+        elements.forEach((element) => {
+            element.addEventListener("touchstart", (e) => this.onTouchStart(e), false);
+            element.addEventListener("touchmove", (e) => this.onTouchMove(e), false);
+            element.addEventListener("touchend", (e) => this.onTouchEnd(e), false);
+            element.addEventListener("touchcancel", () => this.reset(), false);
+        });
+    }
+}