-
Notifications
You must be signed in to change notification settings - Fork 1.9k
Expand file tree
/
Copy pathAXGeometryManager.cpp
More file actions
281 lines (233 loc) · 9.31 KB
/
AXGeometryManager.cpp
File metadata and controls
281 lines (233 loc) · 9.31 KB
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
/*
* Copyright (C) 2023 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "AXGeometryManager.h"
#include "AXLoggerBase.h"
#include "DocumentPage.h"
#if ENABLE(ACCESSIBILITY_ISOLATED_TREE)
#include "AXIsolatedTree.h"
#include "AXObjectCache.h"
#include "Page.h"
#include <array>
#if PLATFORM(MAC)
#include "PlatformScreen.h"
#endif
namespace WebCore {
DEFINE_ALLOCATOR_WITH_HEAP_IDENTIFIER(AXGeometryManager);
AXGeometryManager::AXGeometryManager(AXObjectCache& owningCache)
: m_cache(owningCache)
, m_updateObjectRegionsTimer(*this, &AXGeometryManager::updateObjectRegionsTimerFired)
{
}
AXGeometryManager::AXGeometryManager()
: m_cache(nullptr)
, m_updateObjectRegionsTimer(*this, &AXGeometryManager::updateObjectRegionsTimerFired)
{
}
AXGeometryManager::~AXGeometryManager()
{
if (m_updateObjectRegionsTimer.isActive())
m_updateObjectRegionsTimer.stop();
}
std::optional<IntRect> AXGeometryManager::cachedRectForID(AXID axID)
{
auto rectIterator = m_cachedRects.find(axID);
if (rectIterator != m_cachedRects.end())
return rectIterator->value;
return std::nullopt;
}
bool AXGeometryManager::cacheRectIfNeeded(AXID axID, IntRect&& rect)
{
AX_ASSERT(AXObjectCache::isIsolatedTreeEnabled());
auto rectIterator = m_cachedRects.find(axID);
bool rectChanged = false;
if (rectIterator != m_cachedRects.end()) {
rectChanged = rectIterator->value != rect;
if (rectChanged)
rectIterator->value = rect;
} else {
rectChanged = true;
m_cachedRects.set(axID, rect);
}
if (!rectChanged)
return false;
invalidateHitTestCacheForID(axID);
RefPtr tree = AXIsolatedTree::treeForFrameID(m_cache->frameID());
if (!tree)
return false;
tree->updateFrame(axID, WTF::move(rect));
return true;
}
void AXGeometryManager::scheduleObjectRegionsUpdate(bool scheduleImmediately)
{
if (!scheduleImmediately) [[likely]] {
if (!m_updateObjectRegionsTimer.isActive())
m_updateObjectRegionsTimer.startOneShot(1_s);
return;
}
if (m_updateObjectRegionsTimer.isActive())
m_updateObjectRegionsTimer.stop();
scheduleRenderingUpdate();
}
// The page is about to update accessibility object regions, so the deferred
// update queued with this timer is unnecessary.
void AXGeometryManager::willUpdateObjectRegions()
{
if (m_updateObjectRegionsTimer.isActive())
m_updateObjectRegionsTimer.stop();
if (!m_cache)
return;
if (RefPtr tree = AXIsolatedTree::treeForFrameID(m_cache->frameID()))
tree->updateRootScreenRelativePosition();
}
void AXGeometryManager::scheduleRenderingUpdate()
{
if (!m_cache || !m_cache->document())
return;
if (RefPtr page = m_cache->document()->page())
page->scheduleRenderingUpdate(RenderingUpdateStep::AccessibilityRegionUpdate);
}
#if PLATFORM(MAC)
void AXGeometryManager::initializePrimaryScreenRect()
{
Locker locker { m_primaryScreenRectLock };
m_primaryScreenRect = screenRectForPrimaryScreen();
}
FloatRect AXGeometryManager::primaryScreenRect()
{
Locker locker { m_primaryScreenRectLock };
return m_primaryScreenRect;
}
#endif
std::optional<AXID> AXGeometryManager::cachedHitTestResult(const IntPoint& screenPoint)
{
Locker locker { m_hitTestCacheLock };
static constexpr int MaxCacheRadius = 5;
static constexpr int MaxCacheRadiusSquared = MaxCacheRadius * MaxCacheRadius;
std::optional<AXID> closestMatch;
int closestDistanceSquared = INT_MAX;
auto now = MonotonicTime::now();
// m_hitTestCache contains a mapping of points to elements at those points.
// Iterate the cache to find the closest cached point to |screenPoint|.
// Only consider entries within MaxCacheRadius pixels, and return the
// element at the nearest cached point.
//
// We compare squared distances to test closeness in both x and y, and also
// to avoid expensive sqrt() calls.
//
// e.g., if the |screenPoint| is 3px off in the x-coordinate, and 4px off in the y-coordinate:
// 3² + 4² = 25 — Less than or equal to MaxCacheRadiusSquared, and thus is acceptably close.
// But take the case where the hit-point is 4px off in both x and y:
// 4² + 4² = 32 — Too far from MaxCacheRadiusSquared, so not a match.
for (auto& entry : m_hitTestCache) {
if (now > entry.expirationTime)
continue;
int dx = screenPoint.x() - entry.hitPoint.x();
int dy = screenPoint.y() - entry.hitPoint.y();
int distanceSquared = dx * dx + dy * dy;
if (distanceSquared <= MaxCacheRadiusSquared && distanceSquared < closestDistanceSquared) {
closestDistanceSquared = distanceSquared;
closestMatch = entry.resultID;
}
}
return closestMatch;
}
constexpr MonotonicTime hitTestExpirationTime()
{
return MonotonicTime::now() + Accessibility::HitTestCacheExpiration;
}
void AXGeometryManager::cacheHitTestResult(AXID resultID, const IntPoint& hitPoint)
{
Locker locker { m_hitTestCacheLock };
// Check if we already have an entry for this exact point and update it.
auto now = MonotonicTime::now();
// Also track whether any entries are expired for cleanup.
bool hasExpiredEntries = false;
for (auto& entry : m_hitTestCache) {
if (entry.hitPoint == hitPoint) {
entry.resultID = resultID;
entry.expirationTime = hitTestExpirationTime();
return;
}
if (now > entry.expirationTime)
hasExpiredEntries = true;
}
if (hasExpiredEntries) {
m_hitTestCache.removeAllMatching([now](const HitTestCacheEntry& entry) {
return now > entry.expirationTime;
});
}
// If cache is full, remove the oldest entry (first one, since we append new ones at the end).
if (m_hitTestCache.size() >= HitTestCacheSize)
m_hitTestCache.removeAt(0);
m_hitTestCache.append({ hitPoint, resultID, hitTestExpirationTime() });
}
void AXGeometryManager::expandHitTestCacheAroundPoint(const IntPoint& center, AXTreeID treeID)
{
incrementProbeGeneration();
uint64_t capturedGeneration = currentProbeGeneration();
constexpr int ProbeDistance = 5;
std::array<IntPoint, 4> probePoints = {
IntPoint(center.x() - ProbeDistance, center.y()),
IntPoint(center.x() + ProbeDistance, center.y()),
IntPoint(center.x(), center.y() - ProbeDistance),
IntPoint(center.x(), center.y() + ProbeDistance),
};
for (const auto& probePoint : probePoints) {
// Skip probes with negative coordinates to avoid unnecessary main-thread trips.
if (probePoint.x() < 0 || probePoint.y() < 0)
continue;
ensureOnMainThread([weakThis = ThreadSafeWeakPtr { *this }, probePoint, capturedGeneration, treeID] {
RefPtr protectedThis = weakThis.get();
if (!protectedThis)
return;
// Check if the probe was cancelled by an assistive technology requesting
// a new hit-test location (which will fire new probes from a different spot).
if (protectedThis->currentProbeGeneration() != capturedGeneration)
return;
// Perform hit test.
if (WeakPtr cache = AXTreeStore<AXObjectCache>::axObjectCacheForID(treeID)) {
auto pageRelativePoint = cache->mapScreenPointToPagePoint(probePoint);
RefPtr root = cache->rootWebArea();
if (RefPtr hitResult = root ? root->accessibilityHitTest(pageRelativePoint) : nullptr)
protectedThis->cacheHitTestResult(hitResult->objectID(), probePoint);
}
});
}
}
void AXGeometryManager::invalidateHitTestCacheForID(AXID axID)
{
Locker locker { m_hitTestCacheLock };
m_hitTestCache.removeAllMatching([axID](const HitTestCacheEntry& entry) {
return entry.resultID == axID;
});
}
void AXGeometryManager::clearHitTestCache()
{
Locker locker { m_hitTestCacheLock };
m_hitTestCache.clear();
}
} // namespace WebCore
#endif // ENABLE(ACCESSIBILITY_ISOLATED_TREE)