How Chrome Accessibility Works, Part 3

Follow-up to parts 1 and 2.

This section covers events, actions, hit testing, relative coordinates,
text bounds, and iframes - filling in many of the additional complexity
that was glossed over in parts 1 and 2.

It also adds a few more links to "How Chrome Accessibility Works" from
other Markdown pages.

Bug: None
Change-Id: Ic1037d349555a981d16051526acde36247e32c0f
AX-Relnotes: N/A
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3137196
Commit-Queue: Dominic Mazzoni <[email protected]>
Reviewed-by: David Tseng <[email protected]>
Cr-Commit-Position: refs/heads/main@{#917367}

docs/accessibility.md

@@ -1,6 +1,7 @@
 # Accessibility
 
 * [Accessibility Overview](accessibility/overview.md)
+* [How Chrome Accessibility Works](accessibility/how_a11y_works.md)
 * [Accessibility Tests](accessibility/tests.md)
 
 ## Cross-Platform
@@ -10,10 +11,26 @@
 * [Performance Measurement](accessibility/perf.md)
 * [Reader Mode on Desktop Platforms](accessibility/reader_mode.md)
 
+## Android
+
+* [Chrome accessibility on Android](accessibility/android.md)
+
+## Windows
+
+* [IAccessible2 to UI Automation](accessibility/ia2_to_uia.md)
+* [UI Automation](accessibility/uiautomation.md)
+
 ## Chrome OS
 
+* [Autoclick](accessibility/autoclick.md)
 * [ChromeVox for Developers](accessibility/chromevox.md)
 * [ChromeVox on Desktop Linux](accessibility/chromevox_on_desktop_linux.md)
 * [Updating brltty braille drivers](accessibility/brltty.md)
+* [Select-to-speak](accessibility/select_to_speak.md)
+* [Switch Access](accessibility/switch_access.md)
+
+## Speech synthesis
+
+* [Text-to-speech in Chrome and Chrome OS](accessibility/tts.md)
 * [Updating the espeak speech synthesis engine](accessibility/espeak.md)
 * [Updating the patts speech synthesis engine](accessibility/patts.md)

docs/accessibility/figures/Makefile

@@ -11,7 +11,8 @@ all: \
 	other_multi_process_browser.png \
 	proxy_approach.png \
 	caching_approach.png \
-	multi_process_ax.png
+	multi_process_ax.png \
+	focus_race.png
 
 %.png: %.gv Makefile
 	dot -Tpng $< -o $@

docs/accessibility/figures/focus_race.gv

@@ -0,0 +1,37 @@
+digraph graphname {
+    graph [fontname = "helvetica", fontsize=11, compound=true];
+    node [shape="box", fontname = "helvetica", fontsize=11];
+    edge [fontname = "helvetica", fontsize=11];
+    rankdir="TB";
+
+    subgraph cluster_renderer1 {
+        label = "Render Process 1";
+
+	click1 [label="User clicks on button to open dialog"];
+	dialog1 [label="Dialog opens"];
+	focus1 [label="Button in dialog gets focused"];
+
+	click1 -> dialog1;
+	dialog1 -> focus1;
+    }
+
+    subgraph cluster_renderer2 {
+        label = "Render Process 2";
+
+	click2 [label="User activates window 2"];
+	focus2 [label="Text field in window 2 gets focus"];
+
+	click2 -> focus2;
+    }
+
+    click1 -> click2;
+    focus2 -> browser_focus_2;
+    focus1 -> browser_focus_1;
+
+    subgraph cluster_browser {
+        label = "Browser Process";
+
+        browser_focus_1 [label="Focus event from window 1 button"];
+        browser_focus_2 [label="Focus event from window 2 text field"];
+    }
+}