From 3075888d26d9fbbd56a2615ae51fe8d122ad62b2 Mon Sep 17 00:00:00 2001
From: Constantin Piber <59023762+cpiber@users.noreply.github.com>
Date: Tue, 19 Aug 2025 22:01:31 +0300
Subject: [PATCH] [#1575] Support copy & paste (#1593)

* [#1575] Support paste

* WebView: Implement copy

* Localize copy dialog, lint

* Implement a custom context menu for copy/paste

* Remove click event which causes double events

* WebView: Fix input events broken by moved preventDefault

We want to fall back to the `input` event for Android bug and paste, but
we want to prevent the event for the others, so change the order
---
 .../moko-resources/values/base/strings.xml    |   3 +
 server/src/main/jte/Webview.kte               | 192 ++++++++++++++++--
 .../tachidesk/global/impl/KcefWebView.kt      |  54 ++++-
 .../suwayomi/tachidesk/global/impl/WebView.kt |  16 ++
 4 files changed, 249 insertions(+), 16 deletions(-)

diff --git a/server/i18n/src/commonMain/moko-resources/values/base/strings.xml b/server/i18n/src/commonMain/moko-resources/values/base/strings.xml
index b55c3da5..812cbd9f 100644
--- a/server/i18n/src/commonMain/moko-resources/values/base/strings.xml
+++ b/server/i18n/src/commonMain/moko-resources/values/base/strings.xml
@@ -130,6 +130,7 @@
 
     <string name="label_error">Error</string>
     <string name="label_version">Version <xliff:g id="version" example="v2.0.1833">%1$s</xliff:g></string>
+    <string name="label_close">Close</string>
 
     <string name="webview_label_title">Suwayomi WebView</string>
     <string name="webview_label_disconnected">Disconnected, please refresh</string>
@@ -138,6 +139,8 @@
     <string name="webview_label_init">Initializing... Please wait</string>
     <string name="webview_label_getstarted">Enter a URL to get started</string>
     <string name="webview_label_loading">Loading page...</string>
+    <string name="webview_label_copy">Copy to Clipboard</string>
+    <string name="webview_label_copy_description">Automatic clipboard copy failed, please use the input below to manually copy the value.</string>
     <string name="webview_placeholder_url">Enter URL...</string>
 
     <string name="login_label_title">Suwayomi Login</string>
diff --git a/server/src/main/jte/Webview.kte b/server/src/main/jte/Webview.kte
index 6dfc049a..f4b541c8 100644
--- a/server/src/main/jte/Webview.kte
+++ b/server/src/main/jte/Webview.kte
@@ -131,6 +131,87 @@
         main .status:empty {
             display: none;
         }
+        main .contextmenu {
+            display: none;
+            position: absolute;
+            right: 0;
+            max-width: fit-content;
+            min-height: calc(1.5em + 2px + 2px + 4px);
+            min-width: 120px;
+            flex-wrap: wrap;
+            border-radius: 4px;
+            border: 1px solid #333;
+        }
+        main .contextmenu.show {
+            display: flex;
+        }
+        main .contextmenu button {
+            all: unset;
+            line-height: 1.5;
+            flex-grow: 1;
+            background: white;
+            transition: background 0.1s ease-in-out;
+            cursor: pointer;
+            border: 0.5px solid #666;
+            padding: 2px 4px;
+            text-align: center;
+        }
+        main .contextmenu button:hover {
+            background: #eee;
+        }
+        .copydialog {
+            display: none;
+            position: absolute;
+            inset: 0;
+            width: 100%;
+            height: 100%;
+            padding: 6px;
+        }
+        .copydialog.show {
+            display: block;
+        }
+        .copydialog::before {
+            content: '';
+            position: absolute;
+            inset: 0;
+            background: black;
+            opacity: 0.3;
+        }
+        .copydialog__inner {
+            position: relative;
+            max-width: 960px;
+            border-radius: 8px;
+            border: 1px solid #333;
+            background: #eee;
+            padding: 8px;
+            margin: auto;
+            height: 100%;
+        }
+        .copydialog__title {
+            display: flex;
+            flex-wrap: nowrap;
+            justify-content: space-between;
+        }
+        .copydialog input {
+            width: 100%;
+        }
+        .copydialog .close {
+            flex-shrink: 1;
+            all: unset;
+            cursor: pointer;
+            align-self: start;
+            font-size: 2rem;
+            line-height: 1;
+        }
+        @media (min-width: 500px) {
+            .copydialog {
+                padding: 24px;
+            }
+            .copydialog__inner {
+                padding: 12px 18px;
+                height: auto;
+            }
+        }
 
         /* https://css-tricks.com/snippets/css/css-triangle/ */
         .arrow-right {
@@ -160,10 +241,30 @@
         <div class="status" id="status"></div>
         <canvas id="frame"></canvas>
         <input type="text" id="inputtrap" autocomplete="off"/>
+        <div class="contextmenu" id="contextmenu" role="menu">
+            <button type="button" id="menu_copy" role="menuitem">Copy</button>
+            <button type="button" id="menu_paste" role="menuitem">Paste</button>
+        </div>
     </main>
+    <div class="copydialog" id="copydialog" role="dialog">
+        <div class="copydialog__inner">
+            <div class="copydialog__title">
+                <h2>${MR.strings.webview_label_copy.localized(locale)}</h2>
+                <button type="button" class="close" id="copyclose" title="${MR.strings.label_close.localized(locale)}">&times;</button>
+            </div>
+            <p>${MR.strings.webview_label_copy_description.localized(locale)}</p>
+            <input type="text" id="copyinput" disabled readonly/>
+        </div>
+    </div>
     <script>
         const messageDiv = document.getElementById('message');
         const statusDiv = document.getElementById('status');
+        const copyDiv = document.getElementById('copydialog');
+        const copyInput = document.getElementById('copyinput');
+        const copyClose = document.getElementById('copyclose');
+        const contextMenuDiv = document.getElementById('contextmenu');
+        const contextMenuCopy = document.getElementById('menu_copy');
+        const contextMenuPaste = document.getElementById('menu_paste');
         const frame = document.getElementById('frame');
         const frameInput = document.getElementById('inputtrap');
         const ctx = frame.getContext("2d");
@@ -190,6 +291,34 @@
                 console.error(e);
             }
 
+            copyClose.addEventListener('click', () => {
+                copyDiv.classList.remove('show');
+            });
+
+            contextMenuCopy.addEventListener('click', () => {
+                socket.send(JSON.stringify({
+                    type: 'copy',
+                }));
+                contextMenuDiv.classList.remove('show');
+            });
+
+            contextMenuPaste.addEventListener('click', () => {
+                navigator.clipboard.readText().then(data => {
+                    socket.send(JSON.stringify({
+                        type: 'paste',
+                        data: data,
+                    }));
+                });
+                contextMenuDiv.classList.remove('show');
+            });
+
+            if (!navigator.clipboard || !navigator.clipboard.readText) {
+                // if not served via HTTPS, remove the button, users can still paste via clipboard
+                // e.g. Ctrl+V or the dedicated paste button on gboard
+                // TODO: dialog like with copy?
+                contextMenuPaste.remove();
+            }
+
             /// Helpers
 
             const setHash = (u) => {
@@ -229,6 +358,20 @@
                 ctx.clearRect(0, 0, frame.width, frame.height);
             };
 
+            const copy = (data) => {
+                try {
+                    if (!!navigator.clipboard && !!navigator.clipboard.writeText) {
+                        navigator.clipboard.writeText(data);
+                        return;
+                    }
+                    console.warn('Clipbaord API not supported (not served over HTTPS?), presenting dialog');
+                } catch (e) {
+                    console.error('Clipboard access threw, presenting dialog', e);
+                }
+                copyInput.value = data;
+                copyDiv.classList.add('show');
+            }
+
             /// Form
 
             window.addEventListener('hashchange', e => {
@@ -293,6 +436,9 @@
                         const lg = obj.severity == 4 ? console.error : obj.severity == 3 ? console.warn : console.log;
                         lg(obj.source + ':' + obj.line + ':', obj.message);
                     } break;
+                    case "copy":
+                        copy(obj.content);
+                        break;
                     default:
                         console.warn("Unknown event", obj.type)
                         break;
@@ -322,9 +468,26 @@
             observer.observe(frame);
 
             const frameEvent = (e) => {
-                // Chrome Android bug, see below
+                // Chrome Android bug, see input below
                 if (e.key === "Unidentified") return;
+                // paste is handled in input below
+                if (e.key === "v" && e.ctrlKey === true) return;
+                if (e.key === "c" && e.ctrlKey === true) {
+                    if (e.type === "keydown") {
+                        socket.send(JSON.stringify({
+                            type: 'copy',
+                        }));
+                    }
+                    return;
+                }
                 e.preventDefault();
+                if (e.type === "mousedown" && contextMenuDiv.classList.contains('show')) {
+                    console.log('remove context menu');
+                    contextMenuDiv.classList.remove('show');
+                    return;
+                }
+                // right-click, handled in contextmenu below
+                if (e.type === "mousedown" && e.button === 2) return;
                 const rect = frame.getBoundingClientRect();
                 const clickX = e.clientX !== undefined ? e.clientX - rect.left : 0;
                 const clickY = e.clientY !== undefined ? e.clientY - rect.top : 0;
@@ -348,7 +511,7 @@
 
             const attachEvents = () => {
                 console.log('Attaching event handlers to new document');
-                const events = ["click", "mousedown", "mouseup", "mousemove", "wheel", "keydown", "keyup"];
+                const events = ["mousedown", "mouseup", "mousemove", "wheel", "keydown", "keyup"];
                 for (const ev of events) {
                     frameInput.addEventListener(ev, frameEvent, false);
                 }
@@ -367,7 +530,6 @@
                         e.preventDefault();
                         let deltaX = touch.pageX - e.touches[0].pageX;
                         let deltaY = touch.pageY - e.touches[0].pageY;
-                        console.log(deltaX, deltaY)
                         if (Math.abs(deltaX) > Math.abs(deltaY)) {
                             // assume horizontal scroll
                             socket.send(JSON.stringify({
@@ -400,23 +562,23 @@
                 frameInput.addEventListener('input', e => {
                     e.preventDefault();
                     socket.send(JSON.stringify({
-                        type: 'event',
-                        eventType: 'keydown',
-                        clickX: 0,
-                        clickY: 0,
-                        key: e.data,
-                    }));
-                    socket.send(JSON.stringify({
-                        type: 'event',
-                        eventType: 'keyup',
-                        clickX: 0,
-                        clickY: 0,
-                        key: e.data,
+                        type: 'paste',
+                        data: e.data,
                     }));
                     e.target.value = '';
                 });
                 frameInput.addEventListener('contextmenu', e => {
                     e.preventDefault();
+                    contextMenuDiv.style.left = e.offsetX + 'px';
+                    contextMenuDiv.style.top = e.offsetY + 'px';
+                    contextMenuDiv.classList.add('show');
+
+                    const shiftLeft = contextMenuDiv.offsetParent.offsetWidth - contextMenuDiv.offsetWidth - contextMenuDiv.offsetLeft;
+                    if (shiftLeft < 0)
+                        contextMenuDiv.style.left = (e.offsetX + shiftLeft) + 'px';
+                    const shiftTop = contextMenuDiv.offsetParent.offsetHeight - contextMenuDiv.offsetHeight - contextMenuDiv.offsetTop;
+                    if (shiftTop < 0)
+                        contextMenuDiv.style.top = (e.offsetY + shiftTop) + 'px';
                 }, false);
             };
             attachEvents();
diff --git a/server/src/main/kotlin/suwayomi/tachidesk/global/impl/KcefWebView.kt b/server/src/main/kotlin/suwayomi/tachidesk/global/impl/KcefWebView.kt
index 418acaad..e089f309 100644
--- a/server/src/main/kotlin/suwayomi/tachidesk/global/impl/KcefWebView.kt
+++ b/server/src/main/kotlin/suwayomi/tachidesk/global/impl/KcefWebView.kt
@@ -27,7 +27,10 @@ import org.cef.network.CefCookieManager
 import org.cef.network.CefRequest
 import uy.kohesive.injekt.injectLazy
 import java.awt.Component
+import java.awt.HeadlessException
 import java.awt.Rectangle
+import java.awt.Toolkit
+import java.awt.datatransfer.DataFlavor
 import java.awt.event.InputEvent
 import java.awt.event.KeyEvent
 import java.awt.event.MouseEvent
@@ -113,6 +116,12 @@ class KcefWebView {
         val error: String? = null,
     ) : Event()
 
+    @Serializable
+    @SerialName("copy")
+    private data class CopyEvent(
+        val content: String,
+    ) : Event()
+
     private inner class DisplayHandler : CefDisplayHandlerAdapter() {
         override fun onConsoleMessage(
             browser: CefBrowser,
@@ -346,6 +355,16 @@ class KcefWebView {
         modifier: Int,
     ): KeyEvent? {
         val char = if (msg.key?.length == 1) msg.key[0] else KeyEvent.CHAR_UNDEFINED
+        return keyEvent(char, component, id, modifier, msg.key)
+    }
+
+    private fun keyEvent(
+        char: Char,
+        component: Component,
+        id: Int,
+        modifier: Int,
+        strKey: String? = null,
+    ): KeyEvent? {
         val code =
             when (char.uppercaseChar()) {
                 in 'A'..'Z', in '0'..'9' -> char.uppercaseChar().code
@@ -379,7 +398,7 @@ class KcefWebView {
                 ' ' -> KeyEvent.VK_SPACE
                 '_' -> KeyEvent.VK_UNDERSCORE
                 else ->
-                    when (msg.key) {
+                    when (strKey) {
                         "Alt" -> KeyEvent.VK_ALT
                         "Backspace" -> KeyEvent.VK_BACK_SPACE
                         "Delete" -> KeyEvent.VK_DELETE
@@ -560,6 +579,39 @@ class KcefWebView {
         }
     }
 
+    fun paste(msg: String) {
+        val component = browser?.uiComponent ?: return
+        for (c in msg) {
+            browser!!.sendKeyEvent(keyEvent(c, component, KeyEvent.KEY_PRESSED, 0)!!)
+            keyEvent(c, component, KeyEvent.KEY_TYPED, 0)?.let { browser!!.sendKeyEvent(it) }
+            browser!!.sendKeyEvent(keyEvent(c, component, KeyEvent.KEY_RELEASED, 0)!!)
+        }
+    }
+
+    fun copy() {
+        val frame = browser?.focusedFrame ?: return
+        frame.copy()
+        val clip =
+            try {
+                Toolkit.getDefaultToolkit().getSystemClipboard()
+            } catch (e: HeadlessException) {
+                logger.warn(e) { "Failed to get clipboard" }
+                return
+            }
+        val text =
+            try {
+                clip.getData(DataFlavor.stringFlavor) as String
+            } catch (e: Exception) {
+                logger.warn(e) { "Failed to get clipboard contents" }
+                return
+            }
+        WebView.notifyAllClients(
+            Json.encodeToString<Event>(
+                CopyEvent(text),
+            ),
+        )
+    }
+
     fun canGoBack(): Boolean = browser!!.canGoBack()
 
     fun goBack() {
diff --git a/server/src/main/kotlin/suwayomi/tachidesk/global/impl/WebView.kt b/server/src/main/kotlin/suwayomi/tachidesk/global/impl/WebView.kt
index e7ece31b..d98e7e72 100644
--- a/server/src/main/kotlin/suwayomi/tachidesk/global/impl/WebView.kt
+++ b/server/src/main/kotlin/suwayomi/tachidesk/global/impl/WebView.kt
@@ -79,6 +79,16 @@ object WebView : Websocket<String>() {
         val deltaY: Float? = null,
     ) : TypeObject()
 
+    @Serializable
+    @SerialName("paste")
+    data class JsPasteMessage(
+        val data: String,
+    ) : TypeObject()
+
+    @Serializable
+    @SerialName("copy")
+    class JsCopyMessage : TypeObject()
+
     override fun handleRequest(ctx: WsMessageContext) {
         val dr = driver ?: return
         try {
@@ -97,6 +107,12 @@ object WebView : Websocket<String>() {
                 is JsEventMessage -> {
                     dr.event(event)
                 }
+                is JsPasteMessage -> {
+                    dr.paste(event.data)
+                }
+                is JsCopyMessage -> {
+                    dr.copy()
+                }
             }
         } catch (e: Exception) {
             logger.warn(e) { "Failed to deserialize client request: ${ctx.message()}" }