aboutsummaryrefslogtreecommitdiff
path: root/editors/code/src/inlay_hints.ts
blob: 4581e22782f08011d2429753c5b41cc31dc45d83 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
import * as vscode from 'vscode';
import * as lc from 'vscode-languageclient';
import { Server } from './server';
import { Ctx } from './ctx';

export function activateInlayHints(ctx: Ctx) {
    const hintsUpdater = new HintsUpdater();
    hintsUpdater.refreshHintsForVisibleEditors().then(() => {
        // vscode may ignore top level hintsUpdater.refreshHintsForVisibleEditors()
        // so update the hints once when the focus changes to guarantee their presence
        let editorChangeDisposable: vscode.Disposable | null = null;
        editorChangeDisposable = vscode.window.onDidChangeActiveTextEditor(
            _ => {
                if (editorChangeDisposable !== null) {
                    editorChangeDisposable.dispose();
                }
                return hintsUpdater.refreshHintsForVisibleEditors();
            },
        );

        ctx.pushCleanup(
            vscode.window.onDidChangeVisibleTextEditors(_ =>
                hintsUpdater.refreshHintsForVisibleEditors(),
            ),
        );
        ctx.pushCleanup(
            vscode.workspace.onDidChangeTextDocument(e =>
                hintsUpdater.refreshHintsForVisibleEditors(e),
            ),
        );
        ctx.pushCleanup(
            vscode.workspace.onDidChangeConfiguration(_ =>
                hintsUpdater.toggleHintsDisplay(
                    Server.config.displayInlayHints,
                ),
            ),
        );
    });
}

interface InlayHintsParams {
    textDocument: lc.TextDocumentIdentifier;
}

interface InlayHint {
    range: vscode.Range;
    kind: string;
    label: string;
}

const typeHintDecorationType = vscode.window.createTextEditorDecorationType({
    after: {
        color: new vscode.ThemeColor('ralsp.inlayHint'),
    },
});

class HintsUpdater {
    private displayHints = true;

    public async toggleHintsDisplay(displayHints: boolean): Promise<void> {
        if (this.displayHints !== displayHints) {
            this.displayHints = displayHints;
            return this.refreshVisibleEditorsHints(
                displayHints ? undefined : [],
            );
        }
    }

    public async refreshHintsForVisibleEditors(
        cause?: vscode.TextDocumentChangeEvent,
    ): Promise<void> {
        if (!this.displayHints) return;

        if (
            cause !== undefined &&
            (cause.contentChanges.length === 0 ||
                !this.isRustDocument(cause.document))
        ) {
            return;
        }
        return this.refreshVisibleEditorsHints();
    }

    private async refreshVisibleEditorsHints(
        newDecorations?: vscode.DecorationOptions[],
    ) {
        const promises: Array<Promise<void>> = [];

        for (const rustEditor of vscode.window.visibleTextEditors.filter(
            editor => this.isRustDocument(editor.document),
        )) {
            if (newDecorations !== undefined) {
                promises.push(
                    Promise.resolve(
                        rustEditor.setDecorations(
                            typeHintDecorationType,
                            newDecorations,
                        ),
                    ),
                );
            } else {
                promises.push(this.updateDecorationsFromServer(rustEditor));
            }
        }

        for (const promise of promises) {
            await promise;
        }
    }

    private isRustDocument(document: vscode.TextDocument): boolean {
        return document && document.languageId === 'rust';
    }

    private async updateDecorationsFromServer(
        editor: vscode.TextEditor,
    ): Promise<void> {
        const newHints = await this.queryHints(editor.document.uri.toString());
        if (newHints !== null) {
            const newDecorations = newHints.map(hint => ({
                range: hint.range,
                renderOptions: {
                    after: {
                        contentText: `: ${hint.label}`,
                    },
                },
            }));
            return editor.setDecorations(
                typeHintDecorationType,
                newDecorations,
            );
        }
    }

    private async queryHints(documentUri: string): Promise<InlayHint[] | null> {
        const request: InlayHintsParams = {
            textDocument: { uri: documentUri },
        };
        const client = Server.client;
        return client
            .onReady()
            .then(() =>
                client.sendRequest<InlayHint[] | null>(
                    'rust-analyzer/inlayHints',
                    request,
                ),
            );
    }
}