Move internal packages to an internal folder

For reference: https://go.dev/doc/go1.4#internalpackages

internal/ui/static/js/touch_handler.js

@@ -0,0 +1,187 @@
+class TouchHandler {
+    constructor() {
+        this.reset();
+    }
+
+    reset() {
+        this.touch = {
+            start: { x: -1, y: -1 },
+            move: { x: -1, y: -1 },
+            moved: false,
+            time: 0,
+            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 || this.touch.moved) {
+                return this.touch.move.x - this.touch.start.x;
+            }
+        }
+
+        return 0;
+    }
+
+    findElement(element) {
+        if (element.classList.contains("entry-swipe")) {
+            return element;
+        }
+
+        return DomHelper.findParent(element, "entry-swipe");
+    }
+
+    onItemTouchStart(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);
+        this.touch.element.style.transitionDuration = "0s";
+    }
+
+    onItemTouchMove(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) {
+            this.touch.moved = true;
+
+            let tx = absDistance > 75 ? Math.pow(absDistance - 75, 0.5) + 75 : absDistance;
+
+            if (distance < 0) {
+                tx = -tx;
+            }
+
+            this.touch.element.style.transform = "translateX(" + tx + "px)";
+
+            event.preventDefault();
+        }
+    }
+
+    onItemTouchEnd(event) {
+        if (event.touches === undefined) {
+            return;
+        }
+
+        if (this.touch.element !== null) {
+            let absDistance = Math.abs(this.calculateDistance());
+
+            if (absDistance > 75) {
+                toggleEntryStatus(this.touch.element);
+            }
+
+            if (this.touch.moved) {
+                this.touch.element.style.transitionDuration = "0.15s";
+                this.touch.element.style.transform = "none";
+            }
+        }
+
+        this.reset();
+    }
+
+    onContentTouchStart(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.time = Date.now();
+    }
+
+    onContentTouchMove(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;
+    }
+
+    onContentTouchEnd(event) {
+        if (event.touches === undefined) {
+            return;
+        }
+
+        let distance = this.calculateDistance();
+        let absDistance = Math.abs(distance);
+        let now = Date.now();
+
+        if (now - this.touch.time <= 1000 && absDistance > 75) {
+            if (distance > 0) {
+                goToPage("previous");
+            } else {
+                goToPage("next");
+            }
+        }
+
+        this.reset();
+    }
+
+    onTapEnd(event) {
+        if (event.touches === undefined) {
+            return;
+        }
+
+        let now = Date.now();
+
+        if (this.touch.start.x !== -1 && now - this.touch.time <= 200) {
+            let innerWidthHalf = window.innerWidth / 2;
+
+            if (this.touch.start.x >= innerWidthHalf && event.changedTouches[0].clientX >= innerWidthHalf) {
+                goToPage("next");
+            } else if (this.touch.start.x < innerWidthHalf && event.changedTouches[0].clientX < innerWidthHalf) {
+                goToPage("previous");
+            }
+
+            this.reset();
+        } else {
+            this.reset();
+            this.touch.start.x = event.changedTouches[0].clientX;
+            this.touch.time = now;
+        }
+    }
+
+    listen() {
+        let hasPassiveOption = DomHelper.hasPassiveEventListenerOption();
+
+        let elements = document.querySelectorAll(".entry-swipe");
+
+        elements.forEach((element) => {
+            element.addEventListener("touchstart", (e) => this.onItemTouchStart(e), hasPassiveOption ? { passive: true } : false);
+            element.addEventListener("touchmove", (e) => this.onItemTouchMove(e), hasPassiveOption ? { passive: false } : false);
+            element.addEventListener("touchend", (e) => this.onItemTouchEnd(e), hasPassiveOption ? { passive: true } : false);
+            element.addEventListener("touchcancel", () => this.reset(), hasPassiveOption ? { passive: true } : false);
+        });
+
+        let element = document.querySelector(".entry-content");
+
+        if (element) {
+            if (element.classList.contains("gesture-nav-tap")) {
+                element.addEventListener("touchend", (e) => this.onTapEnd(e), hasPassiveOption ? { passive: true } : false);
+                element.addEventListener("touchmove", () => this.reset(), hasPassiveOption ? { passive: true } : false);
+                element.addEventListener("touchcancel", () => this.reset(), hasPassiveOption ? { passive: true } : false);
+            } else if (element.classList.contains("gesture-nav-swipe")) {
+                element.addEventListener("touchstart", (e) => this.onContentTouchStart(e), hasPassiveOption ? { passive: true } : false);
+                element.addEventListener("touchmove", (e) => this.onContentTouchMove(e), hasPassiveOption ? { passive: true } : false);
+                element.addEventListener("touchend", (e) => this.onContentTouchEnd(e), hasPassiveOption ? { passive: true } : false);
+                element.addEventListener("touchcancel", () => this.reset(), hasPassiveOption ? { passive: true } : false);
+            }
+        }
+    }
+}