ps-blitz-html 0.3.0-beta.3

Blitz HTML parser
Documentation 
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
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296

//! Dragging an overlay scrollbar thumb scrolls the container.

use blitz_dom::{DocumentConfig, EventDriver, NoopEventHandler};
use blitz_html::{HtmlDocument, HtmlProvider};
use blitz_traits::events::{
    BlitzPointerEvent, BlitzPointerId, MouseEventButton, MouseEventButtons, Point, PointerCoords,
    PointerDetails, UiEvent,
};
use blitz_traits::shell::{ColorScheme, Viewport};

use std::sync::Arc;

fn pointer_event(x: f32, y: f32, buttons: MouseEventButtons) -> BlitzPointerEvent {
    BlitzPointerEvent {
        id: BlitzPointerId::Mouse,
        is_primary: true,
        coords: PointerCoords {
            page_x: x,
            page_y: y,
            screen_x: x,
            screen_y: y,
            client_x: x,
            client_y: y,
        },
        button: MouseEventButton::Main,
        buttons,
        mods: Default::default(),
        details: PointerDetails::default(),
        element: Point::default(),
        active_pointers: Default::default(),
    }
}

fn drag(doc: &mut HtmlDocument, from: (f32, f32), to: (f32, f32)) {
    let mut driver = EventDriver::new(doc, NoopEventHandler);
    driver.handle_ui_event(UiEvent::PointerDown(pointer_event(
        from.0,
        from.1,
        MouseEventButtons::Primary,
    )));
    driver.handle_ui_event(UiEvent::PointerMove(pointer_event(
        to.0,
        to.1,
        MouseEventButtons::Primary,
    )));
    driver.handle_ui_event(UiEvent::PointerUp(pointer_event(
        to.0,
        to.1,
        MouseEventButtons::None,
    )));
}

fn scroller_doc() -> HtmlDocument {
    let mut doc = HtmlDocument::from_html(
        r#"<html><body style="margin:0">
            <div id="scroller" style="width:100px; height:100px; overflow-y:auto;">
                <div style="height:1000px;"></div>
            </div>
        </body></html>"#,
        DocumentConfig {
            viewport: Some(Viewport::new(100, 100, 1.0, ColorScheme::Light)),
            html_parser_provider: Some(Arc::new(HtmlProvider) as _),
            ..Default::default()
        },
    );
    doc.resolve(0.0);
    doc
}

/// Scrolls `scroller` down by `dy` content px through the scroll API, which
/// also shows its overlay scrollbars (thumbs are only interactive while
/// visible).
fn scroll_down(doc: &mut HtmlDocument, scroller: usize, dy: f64) {
    doc.scroll_by(Some(scroller), 0.0, -dy, &mut |_| {});
}

#[test]
fn dragging_the_thumb_scrolls_the_container() {
    let mut doc = scroller_doc();
    let scroller = doc.query_selector("#scroller").unwrap().unwrap();

    // Scrolled to 450 (of 900), the 32px thumb sits 34px down its 68px of
    // track play: y in [36, 68] (2px margin).
    scroll_down(&mut doc, scroller, 450.0);
    drag(&mut doc, (97.0, 50.0), (97.0, 16.0));

    let offset = doc.get_node(scroller).unwrap().scroll_offset.y;
    // -34 thumb px * (900 scroll range / 68 track play) = -450 content px
    assert!(
        offset.abs() < 1.0,
        "expected scroll offset ~0 after dragging the thumb up 34px, got {offset}"
    );
}

#[test]
fn dragging_content_does_not_scroll() {
    let mut doc = scroller_doc();
    let scroller = doc.query_selector("#scroller").unwrap().unwrap();

    // Same drag, but starting in the content area, left of the thumb.
    scroll_down(&mut doc, scroller, 450.0);
    drag(&mut doc, (50.0, 50.0), (50.0, 16.0));

    let offset = doc.get_node(scroller).unwrap().scroll_offset.y;
    assert_eq!(offset, 450.0, "content drags must not move the scrollbar");
}

#[test]
fn drag_clamps_at_the_end_of_the_track() {
    let mut doc = scroller_doc();
    let scroller = doc.query_selector("#scroller").unwrap().unwrap();

    scroll_down(&mut doc, scroller, 450.0);
    drag(&mut doc, (97.0, 50.0), (97.0, 500.0));

    let offset = doc.get_node(scroller).unwrap().scroll_offset.y;
    assert!(
        (offset - 900.0).abs() < 1.0,
        "expected scroll offset clamped to 900, got {offset}"
    );
}

#[test]
fn initially_visible_thumb_captures_drags() {
    let mut doc = scroller_doc();
    let scroller = doc.query_selector("#scroller").unwrap().unwrap();

    // Before the first scroll, the thumb is visible for discoverability and
    // must already be interactive.
    drag(&mut doc, (97.0, 8.0), (97.0, 42.0));

    let offset = doc.get_node(scroller).unwrap().scroll_offset.y;
    assert!(
        offset > 0.0,
        "the initially visible thumb must be draggable"
    );
}

#[test]
fn pointer_hover_brightens_the_initial_scrollbar() {
    use anyrender::render_to_buffer;
    use anyrender_vello_cpu::VelloCpuImageRenderer;
    use blitz_paint::paint_scene;

    fn render(doc: &mut HtmlDocument) -> Vec<u8> {
        render_to_buffer::<VelloCpuImageRenderer, _>(
            |scene| paint_scene(scene, doc.as_mut(), 1.0, 100, 100, 0, 0),
            100,
            100,
        )
    }

    let mut doc = scroller_doc();
    let at_rest = render(&mut doc);

    // The initial scrollbar is visible, so hovering its thumb should provide
    // the same feedback as a thumb revealed by scrolling.
    {
        let mut driver = EventDriver::new(&mut doc, NoopEventHandler);
        driver.handle_ui_event(UiEvent::PointerMove(pointer_event(
            95.0,
            8.0,
            MouseEventButtons::None,
        )));
    }
    let hovered = render(&mut doc);

    assert_ne!(at_rest, hovered, "hovering must brighten the initial thumb");
}

#[test]
fn thumb_brightens_on_hover_and_drag() {
    use anyrender::render_to_buffer;
    use anyrender_vello_cpu::VelloCpuImageRenderer;
    use blitz_paint::paint_scene;

    fn thumb_pixel(doc: &mut HtmlDocument) -> [u8; 4] {
        let buffer = render_to_buffer::<VelloCpuImageRenderer, _>(
            |scene| paint_scene(scene, doc.as_mut(), 1.0, 100, 100, 0, 0),
            100,
            100,
        );
        // Scrolled by 50 -> thumb sits around y=8; sample inside it.
        let idx = (8 * 100 + 95) * 4;
        [
            buffer[idx],
            buffer[idx + 1],
            buffer[idx + 2],
            buffer[idx + 3],
        ]
    }

    let mut doc = scroller_doc();
    let scroller = doc.query_selector("#scroller").unwrap().unwrap();
    scroll_down(&mut doc, scroller, 50.0);

    let base = thumb_pixel(&mut doc);

    // Hover the thumb
    {
        let mut driver = EventDriver::new(&mut doc, NoopEventHandler);
        driver.handle_ui_event(UiEvent::PointerMove(pointer_event(
            95.0,
            8.0,
            MouseEventButtons::None,
        )));
    }
    let hovered = thumb_pixel(&mut doc);
    assert_ne!(base, hovered, "thumb must change appearance on hover");

    // Start dragging the thumb
    {
        let mut driver = EventDriver::new(&mut doc, NoopEventHandler);
        driver.handle_ui_event(UiEvent::PointerDown(pointer_event(
            95.0,
            8.0,
            MouseEventButtons::Primary,
        )));
    }
    let active = thumb_pixel(&mut doc);
    assert_ne!(
        hovered, active,
        "thumb must change appearance while dragged"
    );
}

#[test]
#[ignore = "scrollbar-color is hardcoded to auto until stylo exposes it to the servo engine (servo/stylo#413)"]
fn white_author_thumb_still_signals_hover_and_drag() {
    // A near-white `scrollbar-color` thumb can't get lighter: hover/drag
    // feedback must blend towards the pole with contrast headroom (darken).
    use anyrender::render_to_buffer;
    use anyrender_vello_cpu::VelloCpuImageRenderer;
    use blitz_paint::paint_scene;

    fn thumb_pixel(doc: &mut HtmlDocument) -> [u8; 4] {
        let buffer = render_to_buffer::<VelloCpuImageRenderer, _>(
            |scene| paint_scene(scene, doc.as_mut(), 1.0, 100, 100, 0, 0),
            100,
            100,
        );
        let idx = (8 * 100 + 95) * 4;
        [
            buffer[idx],
            buffer[idx + 1],
            buffer[idx + 2],
            buffer[idx + 3],
        ]
    }

    let mut doc = HtmlDocument::from_html(
        r#"<html><body style="margin:0">
            <div id="scroller" style="width:100px; height:100px; overflow-y:auto; scrollbar-color:#ffffff transparent;">
                <div style="height:1000px;"></div>
            </div>
        </body></html>"#,
        DocumentConfig {
            viewport: Some(Viewport::new(100, 100, 1.0, ColorScheme::Light)),
            html_parser_provider: Some(Arc::new(HtmlProvider) as _),
            ..Default::default()
        },
    );
    doc.resolve(0.0);
    let scroller = doc.query_selector("#scroller").unwrap().unwrap();
    scroll_down(&mut doc, scroller, 50.0);

    let base = thumb_pixel(&mut doc);

    {
        let mut driver = EventDriver::new(&mut doc, NoopEventHandler);
        driver.handle_ui_event(UiEvent::PointerMove(pointer_event(
            95.0,
            8.0,
            MouseEventButtons::None,
        )));
    }
    let hovered = thumb_pixel(&mut doc);
    assert_ne!(
        base, hovered,
        "a white author thumb must still visibly change on hover"
    );

    {
        let mut driver = EventDriver::new(&mut doc, NoopEventHandler);
        driver.handle_ui_event(UiEvent::PointerDown(pointer_event(
            95.0,
            8.0,
            MouseEventButtons::Primary,
        )));
    }
    let active = thumb_pixel(&mut doc);
    assert_ne!(
        hovered, active,
        "a white author thumb must still visibly change while dragged"
    );
}