feat(lsp): clearer completion list — source tags, import clubbing, signature docs

src/editor/Editor.js

@@ -96,7 +96,8 @@ define(function (require, exports, module) {
         EditorPreferences = require("./EditorHelper/EditorPreferences"),
         ChangeHelper = require("./EditorHelper/ChangeHelper"),
         ErrorPopupHelper = require("./EditorHelper/ErrorPopupHelper"),
-        InlineWidgetHelper = require("./EditorHelper/InlineWidgetHelper");
+        InlineWidgetHelper = require("./EditorHelper/InlineWidgetHelper"),
+        ScrollbarHelper = require("./EditorHelper/ScrollbarHelper");
 
     /* Editor preferences */
 
@@ -408,6 +409,9 @@ define(function (require, exports, module) {
             // Fail silently; drag image override is non-critical.
         }
 
+        // Click-to-jump on the native scrollbars (instead of slow viewport-at-a-time paging).
+        ScrollbarHelper.installClickToJump(self);
+
         // Can't get CodeMirror's focused state without searching for
         // CodeMirror-focused. Instead, track focus via onFocus and onBlur
         // options and track state with this._focused

src/editor/EditorHelper/ScrollbarHelper.js

@@ -0,0 +1,91 @@
+/*
+ * GNU AGPL-3.0 License
+ *
+ * Copyright (c) 2021 - present core.ai . All rights reserved.
+ * Original work Copyright (c) 2012 - 2021 Adobe Systems Incorporated. All rights reserved.
+ *
+ * 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://opensource.org/licenses/AGPL-3.0.
+ *
+ */
+
+/**
+ * Editor scrollbar behaviour helpers. Only to be used from Editor.js.
+ */
+
+define(function (require, exports, module) {
+
+    /**
+     * Install click-to-jump on an editor's native scrollbars: clicking an empty part of the track
+     * jumps straight to that proportional position, instead of the browser default of paging one
+     * viewport at a time (painfully slow to reach a far-off spot in a large file). A click on the
+     * thumb is left to the native drag.
+     *
+     * CodeMirror's "native" scrollbars are real overflow:scroll <div>s (.CodeMirror-vscrollbar /
+     * .CodeMirror-hscrollbar); setting their scroll offset syncs the editor, since CodeMirror listens
+     * to their scroll event. Unlike most native scrollbars, this webview still delivers mousedown on
+     * them, so we can intercept a track click.
+     *
+     * @param {!Editor} editor
+     */
+    function installClickToJump(editor) {
+        const cm = editor._codeMirror;
+        const wrapper = cm && cm.getWrapperElement();
+        if (!wrapper) {
+            return;
+        }
+
+        // Capture phase so we can suppress the native paging before it runs.
+        wrapper.addEventListener("mousedown", function (e) {
+            const el = e.target;
+            if (e.button !== 0 || !el || !el.classList) {
+                return;
+            }
+            let axis;
+            if (el.classList.contains("CodeMirror-vscrollbar")) {
+                axis = "v";
+            } else if (el.classList.contains("CodeMirror-hscrollbar")) {
+                axis = "h";
+            } else {
+                return;
+            }
+
+            const rect = el.getBoundingClientRect();
+            const view = (axis === "v") ? el.clientHeight : el.clientWidth;   // visible track px
+            const full = (axis === "v") ? el.scrollHeight : el.scrollWidth;   // scrollable px
+            if (full <= view) {
+                return; // nothing to scroll
+            }
+            const cur = (axis === "v") ? el.scrollTop : el.scrollLeft;
+            const thumbStart = (cur / full) * view;
+            const thumbSize = (view / full) * view;
+            const clickPos = (axis === "v") ? (e.clientY - rect.top) : (e.clientX - rect.left);
+            if (clickPos >= thumbStart && clickPos <= thumbStart + thumbSize) {
+                return; // on the thumb - let the native drag handle it
+            }
+
+            // Track click: centre the thumb on the cursor and jump there immediately.
+            let target = (clickPos / view) * full - view / 2;
+            target = Math.max(0, Math.min(target, full - view));
+            e.preventDefault();
+            if (axis === "v") {
+                el.scrollTop = target;
+            } else {
+                el.scrollLeft = target;
+            }
+        }, true);
+        // No explicit removal: the wrapper element is removed on editor.destroy().
+    }
+
+    exports.installClickToJump = installClickToJump;
+});

src/features/ParameterHintsManager.js

@@ -269,8 +269,16 @@ define(function (require, exports, module) {
         }
 
         if (hints.parameters.length > 0) {
-            let token = editor.getToken(hints.functionCallPos);
-            _formatParameterHint(token.string, hints.parameters, appendSeparators, appendParameter);
+            // Prefer a function name supplied by the provider (LSP signatureHelp gives the full
+            // signature label). Only fall back to the editor token for providers that locate the call
+            // site themselves (Tern sets functionCallPos); without that fallback guard, an LSP hint -
+            // whose functionCallPos is undefined - would read the token at the caret, i.e. the just
+            // typed "(", and render an unbalanced "((".
+            let functionName = hints.functionName;
+            if (functionName == null) {
+                functionName = editor.getToken(hints.functionCallPos).string;
+            }
+            _formatParameterHint(functionName, hints.parameters, appendSeparators, appendParameter);
         } else {
             $hintContent.append(_.escape(Strings.NO_ARGUMENTS));
         }