aboutsummaryrefslogtreecommitdiff
path: root/editors/code/src/inlay_hints.ts
blob: f82df66aeda27c16a309affb47e016f011da0525 (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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
import * as vscode from 'vscode';
import * as lc from 'vscode-languageclient';

import { Ctx, sendRequestWithRetry } from './ctx';

export function activateInlayHints(ctx: Ctx) {
    const hintsUpdater = new HintsUpdater(ctx);
    vscode.window.onDidChangeVisibleTextEditors(
        async _ => hintsUpdater.refresh(),
        null,
        ctx.subscriptions
    );

    vscode.workspace.onDidChangeTextDocument(
        async event => {
            if (event.contentChanges.length === 0) return;
            if (event.document.languageId !== 'rust') return;
            await hintsUpdater.refresh();
        },
        null,
        ctx.subscriptions
    );

    vscode.workspace.onDidChangeConfiguration(
        async _ => hintsUpdater.setEnabled(ctx.config.displayInlayHints),
        null,
        ctx.subscriptions
    );

    ctx.pushCleanup({
        dispose() {
            hintsUpdater.clear()
        }
    })

    // XXX: we don't await this, thus Promise rejections won't be handled, but
    // this should never throw in fact...
    hintsUpdater.setEnabled(ctx.config.displayInlayHints)
}

interface InlayHintsParams {
    textDocument: lc.TextDocumentIdentifier;
}

interface InlayHint {
    range: vscode.Range;
    kind: "TypeHint" | "ParameterHint";
    label: string;
}

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

const parameterHintDecorationType = vscode.window.createTextEditorDecorationType({
    before: {
        color: new vscode.ThemeColor('rust_analyzer.inlayHint'),
    }
});

class HintsUpdater {
    private pending = new Map<string, vscode.CancellationTokenSource>();
    private ctx: Ctx;
    private enabled: boolean;

    constructor(ctx: Ctx) {
        this.ctx = ctx;
        this.enabled = false;
    }

    async setEnabled(enabled: boolean): Promise<void> {
        console.log({ enabled, prev: this.enabled });

        if (this.enabled == enabled) return;
        this.enabled = enabled;

        if (this.enabled) {
            return await this.refresh();
        } else {
            return this.clear();
        }
    }

    clear() {
        this.allEditors.forEach(it => {
            this.setTypeDecorations(it, []);
            this.setParameterDecorations(it, []);
        });
    }

    async refresh() {
        if (!this.enabled) return;
        await Promise.all(this.allEditors.map(it => this.refreshEditor(it)));
    }

    private get allEditors(): vscode.TextEditor[] {
        return vscode.window.visibleTextEditors.filter(
            editor => editor.document.languageId === 'rust',
        );
    }

    private async refreshEditor(editor: vscode.TextEditor): Promise<void> {
        const newHints = await this.queryHints(editor.document.uri.toString());
        if (newHints == null) return;

        const newTypeDecorations = newHints
            .filter(hint => hint.kind === 'TypeHint')
            .map(hint => ({
                range: hint.range,
                renderOptions: {
                    after: {
                        contentText: `: ${hint.label}`,
                    },
                },
            }));
        this.setTypeDecorations(editor, newTypeDecorations);

        const newParameterDecorations = newHints
            .filter(hint => hint.kind === 'ParameterHint')
            .map(hint => ({
                range: hint.range,
                renderOptions: {
                    before: {
                        contentText: `${hint.label}: `,
                    },
                },
            }));
        this.setParameterDecorations(editor, newParameterDecorations);
    }

    private setTypeDecorations(
        editor: vscode.TextEditor,
        decorations: vscode.DecorationOptions[],
    ) {
        editor.setDecorations(
            typeHintDecorationType,
            this.enabled ? decorations : [],
        );
    }

    private setParameterDecorations(
        editor: vscode.TextEditor,
        decorations: vscode.DecorationOptions[],
    ) {
        editor.setDecorations(
            parameterHintDecorationType,
            this.enabled ? decorations : [],
        );
    }

    private async queryHints(documentUri: string): Promise<InlayHint[] | null> {
        const client = this.ctx.client;
        if (!client) return null;

        const request: InlayHintsParams = {
            textDocument: { uri: documentUri },
        };
        const tokenSource = new vscode.CancellationTokenSource();
        const prevHintsRequest = this.pending.get(documentUri);
        prevHintsRequest?.cancel();

        this.pending.set(documentUri, tokenSource);
        try {
            return await sendRequestWithRetry<InlayHint[] | null>(
                client,
                'rust-analyzer/inlayHints',
                request,
                tokenSource.token,
            );
        } finally {
            if (!tokenSource.token.isCancellationRequested) {
                this.pending.delete(documentUri);
            }
        }
    }
}