From c61bdf74356781b47f5c47fb55f7906901cdfea7 Mon Sep 17 00:00:00 2001
From: hippoz <paperplanelive@gmail.com>
Date: Fri, 29 Oct 2021 02:03:35 +0300
Subject: [PATCH] add support for holding left click

---
 public/index.html | 51 ++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 42 insertions(+), 9 deletions(-)

diff --git a/public/index.html b/public/index.html
index a39da72..5fae6cb 100644
--- a/public/index.html
+++ b/public/index.html
@@ -6,6 +6,9 @@
     <meta name="viewport" content="user-scalable=no, width=device-width, initial-scale=1, maximum-scale=1">    <title>Document</title>
 
     <script>
+        const HOLDING_THRESHOLD_MS = 175;
+        const SINGLE_CLICK_BUTTON_UP_MS = 5;
+
         const loggerOfType = (components, type='log') => (...args) => {
             let str = '%c';
             const style = 'color: #5e81ac; font-weight: bold;';
@@ -100,6 +103,7 @@
                 this.lastMoveX = 0;
                 this.lastMoveY = 0;
                 this.shouldResetLastMove = false;
+                this.isInHoldingMode = false;
                 this.ongoingTouches = {};
 
                 this.log = Logger(["TouchpadController"], ["log"]).log;
@@ -107,20 +111,31 @@
                 this.connection = connection;
             }
 
+            getButtonCode(button) {
+                let buttonCode = 0;
+                if (button === "right") buttonCode = 1;
+                return buttonCode;
+            }
+
             _sendRelativeMouseMovement(dx, dy) {
                 if (dx === 0 && dy === 0)
                     return;
                 this.connection.sendMessage("r", [dx, dy]);
             }
 
-            _sendSingleClick(button="left") {
-                let buttonCode = 0;
-                if (button === "right") buttonCode = 1;
+            _sendMouseButtonDown(button="left") {
+                this.connection.sendMessage("d", [this.getButtonCode(button)]);
+            }
 
-                this.connection.sendMessage("d", [buttonCode]);
+            _sendMouseButtonUp(button="left") {
+                this.connection.sendMessage("u", [this.getButtonCode(button)]);
+            }
+
+            _sendSingleClick(button="left") {
+                this._sendMouseButtonDown(button);
                 setTimeout(
-                    () =>this.connection.sendMessage("u", [buttonCode]),
-                    5
+                    () => this._sendMouseButtonUp(button),
+                    SINGLE_CLICK_BUTTON_UP_MS
                 );
             }
 
@@ -154,9 +169,17 @@
 
             onTouchEnd({ changedTouches }) {
                 this.shouldResetLastMove = true;
-                // A single tap = left click
-                if (changedTouches.length === 1 && !this.ongoingTouches[changedTouches[0].identifier].hasMoved)
-                    this._sendSingleClick("left");
+                if (changedTouches.length === 1) {
+                    // This is a single tap - left click
+                    if (!this.ongoingTouches[changedTouches[0].identifier].hasMoved) {
+                        this._sendSingleClick("left");
+                    // We were in "holding mode" and now that touch event has ended,
+                    // thus we have to stop holding the left click button
+                    } else if (this.isInHoldingMode) {
+                        this._sendMouseButtonUp("left");
+                        this.isInHoldingMode = false;
+                    }
+                }
                 for (let i = 0; i < changedTouches.length; i++) {
                     const touch = changedTouches[i];
                     this.ongoingTouches[touch.identifier] = null;
@@ -173,6 +196,16 @@
                         clientY: touch.clientY,
                         hasMoved: false
                     };
+
+                    // If the touch is still unmoved and held for a certain amount of time,
+                    // we will enter "holding mode" which keeps the mouse button held while dragging
+                    // allowing you to, for example, select text or drag a scrollbar
+                    setTimeout(() => {
+                        if (this.ongoingTouches[touch.identifier] && !this.ongoingTouches[touch.identifier].hasMoved) {
+                            this.isInHoldingMode = true;
+                            this._sendMouseButtonDown("left");
+                        }
+                    }, HOLDING_THRESHOLD_MS);
                 }
             }
         }