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Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <AK/FileSystemPath.h>
28#include <LibCore/File.h>
29#include <LibGUI/Application.h>
30#include <LibGUI/Painter.h>
31#include <LibGUI/ScrollBar.h>
32#include <LibGUI/Window.h>
33#include <LibGfx/PNGLoader.h>
34#include <LibHTML/DOM/Element.h>
35#include <LibHTML/DOM/ElementFactory.h>
36#include <LibHTML/DOM/HTMLAnchorElement.h>
37#include <LibHTML/DOM/HTMLImageElement.h>
38#include <LibHTML/DOM/Text.h>
39#include <LibHTML/Dump.h>
40#include <LibHTML/Frame.h>
41#include <LibHTML/HtmlView.h>
42#include <LibHTML/Layout/LayoutDocument.h>
43#include <LibHTML/Layout/LayoutNode.h>
44#include <LibHTML/Parser/HTMLParser.h>
45#include <LibHTML/RenderingContext.h>
46#include <LibHTML/ResourceLoader.h>
47#include <stdio.h>
48
49HtmlView::HtmlView()
50 : m_main_frame(::Frame::create(*this))
51{
52 main_frame().on_set_needs_display = [this](auto& content_rect) {
53 if (content_rect.is_empty()) {
54 update();
55 return;
56 }
57 Gfx::Rect adjusted_rect = content_rect;
58 adjusted_rect.set_location(to_widget_position(content_rect.location()));
59 update(adjusted_rect);
60 };
61
62 set_should_hide_unnecessary_scrollbars(true);
63 set_background_role(ColorRole::Base);
64}
65
66HtmlView::~HtmlView()
67{
68}
69
70void HtmlView::set_document(Document* new_document)
71{
72 RefPtr<Document> old_document = document();
73
74 if (new_document == old_document)
75 return;
76
77 if (old_document)
78 old_document->on_layout_updated = nullptr;
79
80 main_frame().set_document(new_document);
81
82 if (new_document) {
83 new_document->on_layout_updated = [this] {
84 layout_and_sync_size();
85 update();
86 };
87 }
88
89#ifdef HTML_DEBUG
90 if (document != nullptr) {
91 dbgprintf("\033[33;1mLayout tree before layout:\033[0m\n");
92 ::dump_tree(*layout_root());
93 }
94#endif
95
96 layout_and_sync_size();
97 update();
98}
99
100void HtmlView::layout_and_sync_size()
101{
102 if (!document())
103 return;
104
105 bool had_vertical_scrollbar = vertical_scrollbar().is_visible();
106 bool had_horizontal_scrollbar = horizontal_scrollbar().is_visible();
107
108 main_frame().set_size(available_size());
109 document()->layout();
110 set_content_size(enclosing_int_rect(layout_root()->rect()).size());
111
112 // NOTE: If layout caused us to gain or lose scrollbars, we have to lay out again
113 // since the scrollbars now take up some of the available space.
114 if (had_vertical_scrollbar != vertical_scrollbar().is_visible() || had_horizontal_scrollbar != horizontal_scrollbar().is_visible()) {
115 main_frame().set_size(available_size());
116 document()->layout();
117 set_content_size(enclosing_int_rect(layout_root()->rect()).size());
118 }
119
120 main_frame().set_viewport_rect(visible_content_rect());
121
122#ifdef HTML_DEBUG
123 dbgprintf("\033[33;1mLayout tree after layout:\033[0m\n");
124 ::dump_tree(*layout_root());
125#endif
126}
127
128void HtmlView::resize_event(GUI::ResizeEvent& event)
129{
130 GUI::ScrollableWidget::resize_event(event);
131 layout_and_sync_size();
132}
133
134void HtmlView::paint_event(GUI::PaintEvent& event)
135{
136 GUI::Frame::paint_event(event);
137
138 GUI::Painter painter(*this);
139 painter.add_clip_rect(widget_inner_rect());
140 painter.add_clip_rect(event.rect());
141
142 if (!layout_root()) {
143 painter.fill_rect(event.rect(), palette().color(background_role()));
144 return;
145 }
146
147 painter.fill_rect(event.rect(), document()->background_color(palette()));
148
149 if (auto background_bitmap = document()->background_image()) {
150 painter.draw_tiled_bitmap(event.rect(), *background_bitmap);
151 }
152
153 painter.translate(frame_thickness(), frame_thickness());
154 painter.translate(-horizontal_scrollbar().value(), -vertical_scrollbar().value());
155
156 RenderingContext context(painter, palette());
157 context.set_should_show_line_box_borders(m_should_show_line_box_borders);
158 context.set_viewport_rect(visible_content_rect());
159 layout_root()->render(context);
160}
161
162void HtmlView::mousemove_event(GUI::MouseEvent& event)
163{
164 if (!layout_root())
165 return GUI::ScrollableWidget::mousemove_event(event);
166
167 bool hovered_node_changed = false;
168 bool is_hovering_link = false;
169 bool was_hovering_link = document()->hovered_node() && document()->hovered_node()->is_link();
170 auto result = layout_root()->hit_test(to_content_position(event.position()));
171 const HTMLAnchorElement* hovered_link_element = nullptr;
172 if (result.layout_node) {
173 auto* node = result.layout_node->node();
174 hovered_node_changed = node != document()->hovered_node();
175 document()->set_hovered_node(const_cast<Node*>(node));
176 if (node) {
177 hovered_link_element = node->enclosing_link_element();
178 if (hovered_link_element) {
179#ifdef HTML_DEBUG
180 dbg() << "HtmlView: hovering over a link to " << hovered_link_element->href();
181#endif
182 is_hovering_link = true;
183 }
184 }
185 if (m_in_mouse_selection) {
186 layout_root()->selection().set_end({ result.layout_node, result.index_in_node });
187 dump_selection("MouseMove");
188 update();
189 }
190 }
191 if (window())
192 window()->set_override_cursor(is_hovering_link ? GUI::StandardCursor::Hand : GUI::StandardCursor::None);
193 if (hovered_node_changed) {
194 update();
195 auto* hovered_html_element = document()->hovered_node() ? document()->hovered_node()->enclosing_html_element() : nullptr;
196 if (hovered_html_element && !hovered_html_element->title().is_null()) {
197 auto screen_position = screen_relative_rect().location().translated(event.position());
198 GUI::Application::the().show_tooltip(hovered_html_element->title(), screen_position.translated(4, 4));
199 } else {
200 GUI::Application::the().hide_tooltip();
201 }
202 }
203 if (is_hovering_link != was_hovering_link) {
204 if (on_link_hover) {
205 on_link_hover(hovered_link_element ? document()->complete_url(hovered_link_element->href()).to_string() : String());
206 }
207 }
208 event.accept();
209}
210
211void HtmlView::mousedown_event(GUI::MouseEvent& event)
212{
213 if (!layout_root())
214 return GUI::ScrollableWidget::mousemove_event(event);
215
216 bool hovered_node_changed = false;
217 auto result = layout_root()->hit_test(to_content_position(event.position()));
218 if (result.layout_node) {
219 auto* node = result.layout_node->node();
220 hovered_node_changed = node != document()->hovered_node();
221 document()->set_hovered_node(const_cast<Node*>(node));
222 if (node) {
223 if (auto* link = node->enclosing_link_element()) {
224 dbg() << "HtmlView: clicking on a link to " << link->href();
225 if (on_link_click)
226 on_link_click(link->href());
227 } else {
228 if (event.button() == GUI::MouseButton::Left) {
229 layout_root()->selection().set({ result.layout_node, result.index_in_node }, {});
230 dump_selection("MouseDown");
231 m_in_mouse_selection = true;
232 }
233 }
234 }
235 }
236 if (hovered_node_changed)
237 update();
238 event.accept();
239}
240
241void HtmlView::mouseup_event(GUI::MouseEvent& event)
242{
243 if (!layout_root())
244 return GUI::ScrollableWidget::mouseup_event(event);
245
246 if (event.button() == GUI::MouseButton::Left) {
247 dump_selection("MouseUp");
248 m_in_mouse_selection = false;
249 }
250}
251
252void HtmlView::keydown_event(GUI::KeyEvent& event)
253{
254 if (event.modifiers() == 0) {
255 switch (event.key()) {
256 case Key_Home:
257 vertical_scrollbar().set_value(0);
258 break;
259 case Key_End:
260 vertical_scrollbar().set_value(vertical_scrollbar().max());
261 break;
262 case Key_Down:
263 vertical_scrollbar().set_value(vertical_scrollbar().value() + vertical_scrollbar().step());
264 break;
265 case Key_Up:
266 vertical_scrollbar().set_value(vertical_scrollbar().value() - vertical_scrollbar().step());
267 break;
268 case Key_Left:
269 horizontal_scrollbar().set_value(horizontal_scrollbar().value() + horizontal_scrollbar().step());
270 break;
271 case Key_Right:
272 horizontal_scrollbar().set_value(horizontal_scrollbar().value() - horizontal_scrollbar().step());
273 break;
274 case Key_PageDown:
275 vertical_scrollbar().set_value(vertical_scrollbar().value() + frame_inner_rect().height());
276 break;
277 case Key_PageUp:
278 vertical_scrollbar().set_value(vertical_scrollbar().value() - frame_inner_rect().height());
279 break;
280 }
281 }
282
283 event.accept();
284}
285
286void HtmlView::reload()
287{
288 load(main_frame().document()->url());
289}
290
291static RefPtr<Document> create_image_document(const ByteBuffer& data, const URL& url)
292{
293 auto document = adopt(*new Document);
294 document->set_url(url);
295
296 auto bitmap = Gfx::load_png_from_memory(data.data(), data.size());
297 ASSERT(bitmap);
298
299 auto html_element = create_element(document, "html");
300 document->append_child(html_element);
301
302 auto head_element = create_element(document, "head");
303 html_element->append_child(head_element);
304 auto title_element = create_element(document, "title");
305 head_element->append_child(title_element);
306
307 auto basename = FileSystemPath(url.path()).basename();
308 auto title_text = adopt(*new Text(document, String::format("%s [%dx%d]", basename.characters(), bitmap->width(), bitmap->height())));
309 title_element->append_child(title_text);
310
311 auto body_element = create_element(document, "body");
312 html_element->append_child(body_element);
313
314 auto image_element = create_element(document, "img");
315 image_element->set_attribute("src", url.to_string());
316 body_element->append_child(image_element);
317
318 return document;
319}
320
321void HtmlView::load(const URL& url)
322{
323 dbg() << "HtmlView::load: " << url;
324
325 if (window())
326 window()->set_override_cursor(GUI::StandardCursor::None);
327
328 if (on_load_start)
329 on_load_start(url);
330
331 ResourceLoader::the().load(url, [this, url](auto data) {
332 if (data.is_null()) {
333 dbg() << "Load failed!";
334 ASSERT_NOT_REACHED();
335 }
336
337 RefPtr<Document> document;
338 if (url.path().ends_with(".png")) {
339 document = create_image_document(data, url);
340 } else {
341 document = parse_html_document(data, url);
342 }
343 ASSERT(document);
344 set_document(document);
345 if (on_title_change)
346 on_title_change(document->title());
347 });
348}
349
350const LayoutDocument* HtmlView::layout_root() const
351{
352 return document() ? document()->layout_node() : nullptr;
353}
354
355LayoutDocument* HtmlView::layout_root()
356{
357 if (!document())
358 return nullptr;
359 return const_cast<LayoutDocument*>(document()->layout_node());
360}
361
362void HtmlView::scroll_to_anchor(const StringView& name)
363{
364 if (!document())
365 return;
366
367 auto* element = document()->get_element_by_id(name);
368 if (!element) {
369 auto candidates = document()->get_elements_by_name(name);
370 for (auto* candidate : candidates) {
371 if (is<HTMLAnchorElement>(*candidate)) {
372 element = to<HTMLAnchorElement>(candidate);
373 break;
374 }
375 }
376 }
377
378 if (!element) {
379 dbg() << "HtmlView::scroll_to_anchor(): Anchor not found: '" << name << "'";
380 return;
381 }
382 if (!element->layout_node()) {
383 dbg() << "HtmlView::scroll_to_anchor(): Anchor found but without layout node: '" << name << "'";
384 return;
385 }
386 auto& layout_node = *element->layout_node();
387 Gfx::FloatRect float_rect { layout_node.box_type_agnostic_position(), { (float)visible_content_rect().width(), (float)visible_content_rect().height() } };
388 scroll_into_view(enclosing_int_rect(float_rect), true, true);
389 window()->set_override_cursor(GUI::StandardCursor::None);
390}
391
392Document* HtmlView::document()
393{
394 return main_frame().document();
395}
396
397const Document* HtmlView::document() const
398{
399 return main_frame().document();
400}
401
402void HtmlView::dump_selection(const char* event_name)
403{
404 dbg() << event_name << " selection start: "
405 << layout_root()->selection().start().layout_node << ":" << layout_root()->selection().start().index_in_node << ", end: "
406 << layout_root()->selection().end().layout_node << ":" << layout_root()->selection().end().index_in_node;
407}
408
409void HtmlView::did_scroll()
410{
411 main_frame().set_viewport_rect(visible_content_rect());
412}