Add comprehensive Android accessibility support following RetroArch's proven
architecture to enable screen reader functionality for visually impaired players.
The implementation uses Android's native accessibility framework (announceForAccessibility)
to integrate with TalkBack and other screen readers, providing the same accessibility
features available on Windows (Tolk) and Linux (speech-dispatcher).
## Functionality Status
✅ **Working:**
- Compiles successfully for all Android architectures
- TTS starts correctly after game data loading
- TTS interrupts speech when needed (using appropriate `force=true`)
- TTS uses Android's default text-to-speech engine
⚠️ **Known Issues (mod-related, not TTS):**
- Stats screen navigation: pressing C or equivalent button focuses on "Strength"
and prevents navigation through other attributes
- Tracking keys provide incorrect/imprecise directions, preventing proper navigation
to desired destinations
- Mod sounds (doors, chests) not playing - likely due to incorrect file paths or
Android-specific issues
See #12 for details on known issues.
## Usage Instructions
⚠️ **IMPORTANT:** To play, you must suspend the screen reader (TalkBack) after
loading the game data (.mpq). The accessibility mod takes control of TTS through
Android's native API.
## Key Technical Changes
• Added JNI bridge between C++ game code and Java accessibility APIs
• Implemented thread-safe JNIEnv caching with pthread thread-local storage
• Created native methods for screen reader detection and text-to-speech
• Fixed initialization order: nativeInitAccessibility() must be called after
super.onCreate() to ensure SDL loads the native library first
• Enabled SCREEN_READER_INTEGRATION flag in Android CMake configuration
## Technical Details
- Java Layer (DevilutionXSDLActivity.java):
• isScreenReaderEnabled(): Checks TalkBack and touch exploration state
• accessibilitySpeak(): Uses announceForAccessibility() API
- JNI Bridge (Source/platform/android/android.cpp):
• GetJNI(): Thread-safe JNIEnv retrieval with automatic thread attachment
• SpeakTextAndroid(): Calls Java accessibilitySpeak() from C++
• IsScreenReaderEnabledAndroid(): Queries TalkBack status from native code
- Platform Integration (Source/utils/screen_reader.cpp):
• Routes accessibility calls to platform-specific implementations
• Maintains consistent API across Windows, Linux, and Android
## Architecture Notes
- Follows RetroArch's accessibility implementation pattern
- Uses global JNI references for thread-safe Activity access
- Caches method IDs to avoid repeated JNI lookups
- Handles thread attachment/detachment automatically
- No external dependencies required (Android SDK only)
## Documentation
Added comprehensive technical documentation in docs/ANDROID_ACCESSIBILITY.md
Fixes startup crash caused by calling native methods before library loading.
Verified on physical device: app launches successfully, accessibility features functional.
Closes#12
```
Add comprehensive Android accessibility support following RetroArch's proven
architecture to enable screen reader functionality for visually impaired players.
The implementation uses Android's native accessibility framework (announceForAccessibility)
to integrate with TalkBack and other screen readers, providing the same accessibility
features available on Windows (Tolk) and Linux (speech-dispatcher).
## Functionality Status
✅ **Working:**
- Compiles successfully for all Android architectures
- TTS starts correctly after game data loading
- TTS interrupts speech when needed (using appropriate `force=true`)
- TTS uses Android's default text-to-speech engine
⚠️ **Known Issues (mod-related, not TTS):**
- Stats screen navigation: pressing C or equivalent button focuses on "Strength"
and prevents navigation through other attributes
- Tracking keys provide incorrect/imprecise directions, preventing proper navigation
to desired destinations
- Mod sounds (doors, chests) not playing - likely due to incorrect file paths or
Android-specific issues
See #12 for details on known issues.
## Usage Instructions
⚠️ **IMPORTANT:** To play, you must suspend the screen reader (TalkBack) after
loading the game data (.mpq). The accessibility mod takes control of TTS through
Android's native API.
## Key Technical Changes
• Added JNI bridge between C++ game code and Java accessibility APIs
• Implemented thread-safe JNIEnv caching with pthread thread-local storage
• Created native methods for screen reader detection and text-to-speech
• Fixed initialization order: nativeInitAccessibility() must be called after
super.onCreate() to ensure SDL loads the native library first
• Enabled SCREEN_READER_INTEGRATION flag in Android CMake configuration
## Technical Details
- Java Layer (DevilutionXSDLActivity.java):
• isScreenReaderEnabled(): Checks TalkBack and touch exploration state
• accessibilitySpeak(): Uses announceForAccessibility() API
- JNI Bridge (Source/platform/android/android.cpp):
• GetJNI(): Thread-safe JNIEnv retrieval with automatic thread attachment
• SpeakTextAndroid(): Calls Java accessibilitySpeak() from C++
• IsScreenReaderEnabledAndroid(): Queries TalkBack status from native code
- Platform Integration (Source/utils/screen_reader.cpp):
• Routes accessibility calls to platform-specific implementations
• Maintains consistent API across Windows, Linux, and Android
## Architecture Notes
- Follows RetroArch's accessibility implementation pattern
- Uses global JNI references for thread-safe Activity access
- Caches method IDs to avoid repeated JNI lookups
- Handles thread attachment/detachment automatically
- No external dependencies required (Android SDK only)
## Documentation
Added comprehensive technical documentation in docs/ANDROID_ACCESSIBILITY.md
Fixes startup crash caused by calling native methods before library loading.
Verified on physical device: app launches successfully, accessibility features functional.
Related files:
• CMake/Dependencies.cmake: Skip external dependencies for Android
• Source/CMakeLists.txt: Add Android-specific screen reader configuration
• android-project/app/build.gradle: Enable SCREEN_READER_INTEGRATION flag
In C++, globals initialization order accross translation units is not
defined. Accessing a global via a function ensures that it is initialized.
This will be needed for #7638, which will statically initialize change
handlers after the Options object has been initialized.
This does not fully address the issue of most everything
being a giant library but it's a start.
Note that the libraries are OBJECT libraries, so they
may (and currently do) contain references to missing
symbols.
Also fixes the implementation of transitive dependency
support for OBJECT libraries.
Replaces `NXDK` ifdefs that relate to the lack of wchar APIs
with the more general `DEVILUTIONX_WINDOWS_NO_WCHAR` ifdefs.
This should make it much easier to port to Windows 98.
Done with the following script:
```ruby
Dir["Source/**/*.{h,c,cc,cpp,hpp}"].each do |path|
v = File.read(path)
next if !v.include?("uint32_t") || v.include?("cstdint")
lines = v.lines
line_num = if lines[2].start_with?(" *")
lines.index { |l| l.start_with?(" */") } + 3
else
3
end
lines.insert(line_num, "#include <cstdint>\n")
File.write(path, lines.join(""))
end
```
then fixed-up manually
Adds simple string / integer concatenation functions.
Many of the uses of `fmt::format` are simply concatenation
of a few strings and integers.
`StrCat` is an easier-to-read alternative to such uses of `fmt`.
Reduces the size of the `PathNodes` array from 28 KiB to just 8 KiB.
Also reduces the size of `pnode_tblptr` from `300 * sizeof(void *)` to
`300 * 2` bytes.
The C++ `std::locale("")` constructor performs a static
initialization of all the facets on the first call.
For example, this includes things like currency formatting.
Avoid all of that by using the environment variables with a fallback to
the equivalent C locale call.
This variable is controlled/set by the code in that file, this also lets other files have more specific/relevant includes instead of the monolith that is diablo.h
Was this meant to reset the output? It should never be changed unless the user confirms input. In practice this was calling memcpy with the same src and dest pointers, which is undefined behaviour.
Juan Mathews
Yuri Pourre
LP
Gleb Mazovetskiy
Anders Jenbo
qndel
staphen
Andrew James
John Törnblom