## Summary
Ref comment:
https://github.com/crosspoint-reader/crosspoint-reader/pull/1010#pullrequestreview-3828854640
This PR introduces `ActivityManager`, which mirrors the same concept of
Activity in Android, where an activity represents a single screen of the
UI. The manager is responsible for launching activities, and ensuring
that only one activity is active at a time.
Main differences from Android's ActivityManager:
- No concept of Bundle or Intent extras
- No onPause/onResume, since we don't have a concept of background
activities
- onActivityResult is implemented via a callback instead of a separate
method, for simplicity
## Key changes
- Single `renderTask` shared across all activities
- No more sub-activity, we manage them using a stack; Results can be
passed via `startActivityForResult` and `setResult`
- Activity can call `finish()` to destroy themself, but the actual
deletion will be handled by `ActivityManager` to avoid `delete this`
pattern
As a bonus: the manager will automatically call `requestUpdate()` when
returning from another activity
## Example usage
**BEFORE**:
```cpp
// caller
enterNewActivity(new WifiSelectionActivity(renderer, mappedInput,
[this](const bool connected) { onWifiSelectionComplete(connected); }));
// subactivity
onComplete(true); // will eventually call exitActivity(), which deletes the caller instance (dangerous behavior)
```
**AFTER**: (mirrors the `startActivityForResult` and `setResult` from
android)
```cpp
// caller
startActivityForResult(new NetworkModeSelectionActivity(renderer, mappedInput),
[this](const ActivityResult& result) { onNetworkModeSelected(result.selectedNetworkMode); });
// subactivity
ActivityResult result;
result.isCancelled = false;
result.selectedNetworkMode = mode;
setResult(result);
finish(); // signals to ActivityManager to go back to last activity AFTER this function returns
```
TODO:
- [x] Reconsider if the `Intent` is really necessary or it should be
removed (note: it's inspired by
[Intent](https://developer.android.com/guide/components/intents-common)
from Android API) ==> I decided to keep this pattern fr clarity
- [x] Verify if behavior is still correct (i.e. back from sub-activity)
- [x] Refactor the `ActivityWithSubactivity` to just simple `Activity`
--> We are using a stack for keeping track of sub-activity now
- [x] Use single task for rendering --> avoid allocating 8KB stack per
activity
- [x] Implement the idea of [Activity
result](https://developer.android.com/training/basics/intents/result)
--> Allow sub-activity like Wifi to report back the status (connected,
failed, etc)
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? **PARTIALLY**, some
repetitive migrations are done by Claude, but I'm the one how ultimately
approve it
---------
Co-authored-by: Zach Nelson <zach@zdnelson.com>
## Summary
Currently, each activity has to manage their own `displayTaskLoop` which
adds redundant boilerplate code. The loop is a wait loop which is also
not the best practice, as the `updateRequested` boolean is not protected
by a mutex.
In this PR:
- Move `displayTaskLoop` to the super `Activity` class
- Replace `updateRequested` with freeRTOS's [direct to task
notification](https://www.freertos.org/Documentation/02-Kernel/02-Kernel-features/03-Direct-to-task-notifications/01-Task-notifications)
- For `ActivityWithSubactivity`, whenever a sub-activity is present, the
parent's `render()` automatically goes inactive
With this change, activities now only need to expose `render()`
function, and anywhere in the code base can call `requestUpdate()` to
request a new rendering pass.
## Additional Context
In theory, this change may also make the battery life a bit better,
since one wait loop is removed. Although the equipment in my home lab
wasn't been able to verify it (the electric current is too noisy and
small). Would appreciate if anyone has any insights on this subject.
Update: I managed to hack [a small piece of
code](https://github.com/ngxson/crosspoint-reader/tree/xsn/measure_cpu_usage)
that allow tracking CPU idle time.
The CPU load does decrease a bit (1.47% down to 1.39%), which make
sense, because the display task is now sleeping most of the time unless
notified. This should translate to a slightly increase in battery life
in the long run.
```
PR:
[40012] [MEM] Free: 185856 bytes, Total: 231004 bytes, Min Free: 123316 bytes
[40012] [IDLE] Idle time: 98.61% (CPU load: 1.39%)
[50017] [MEM] Free: 185856 bytes, Total: 231004 bytes, Min Free: 123316 bytes
[50017] [IDLE] Idle time: 98.61% (CPU load: 1.39%)
[60022] [MEM] Free: 185856 bytes, Total: 231004 bytes, Min Free: 123316 bytes
[60022] [IDLE] Idle time: 98.61% (CPU load: 1.39%)
master:
[20012] [MEM] Free: 195016 bytes, Total: 231532 bytes, Min Free: 132460 bytes
[20012] [IDLE] Idle time: 98.53% (CPU load: 1.47%)
[30017] [MEM] Free: 195016 bytes, Total: 231532 bytes, Min Free: 132460 bytes
[30017] [IDLE] Idle time: 98.53% (CPU load: 1.47%)
[40022] [MEM] Free: 195016 bytes, Total: 231532 bytes, Min Free: 132460 bytes
[40022] [IDLE] Idle time: 98.53% (CPU load: 1.47%)
```
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? **NO**
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Refactor**
* Streamlined rendering architecture by consolidating update mechanisms
across all activities, improving efficiency and consistency.
* Modernized synchronization patterns for display updates to ensure
reliable, conflict-free rendering.
* **Bug Fixes**
* Enhanced rendering stability through improved locking mechanisms and
explicit update requests.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---------
Co-authored-by: znelson <znelson@users.noreply.github.com>
## Summary
- **What is the goal of this PR?** Add chapter selection support to the
XTC reader activity, including parsing chapter metadata from XTC files.
- **What changes are included?** Implemented XTC chapter parsing and
exposure in the XTC library, added a chapter selection activity for XTC,
integrated it into XtcReaderActivity, and normalized chapter page
indices by shifting them to 0-based.
## Additional Context
- The reader uses 0-based page indexing (first page = 0), but the XTC
chapter table appears to be 1-based (first page = 1), so chapter
start/end pages are shifted down by 1 during parsing.
## Summary
**What is the goal of this PR?**
Adds a setting to swap the front buttons. The default functionality are:
Back/Confirm/Left/Right. When this setting is enabled they become:
Left/Right/Back/Confirm. This makes it more comfortable to use when
holding in your right hand since your thumb can more easily rest on the
next button. The original firmware has a similar setting.
**What changes are included?**
- Add the new setting.
- Create a mapper to dynamically switch the buttons based on the
setting.
- Use mapper on the various activity screens.
- Update the button hints to reflect the swapped buttons.
## Additional Context
Full disclosure: I used Codex CLI to put this PR together, but did
review it to make sure it makes sense.
Also tested on my device:
https://share.cleanshot.com/k76891NY
## Summary
* **What is the goal of this PR?**
Add support for XTC (XTeink X4 native) ebook format, which contains
pre-rendered 480x800 1-bit bitmap pages optimized for e-ink displays.
* **What changes are included?**
- New `lib/Xtc/` library with XtcParser for reading XTC files
- XtcReaderActivity for displaying XTC pages on e-ink display
- XTC file detection in FileSelectionActivity
- Cover BMP generation from first XTC page
- Correct XTG page header structure (22 bytes) and bit polarity handling
## Additional Context
- XTC files contain pre-rendered bitmap pages with embedded status bar
(page numbers, progress %)
- XTG page header: 22 bytes (magic + dimensions + reserved fields +
bitmap size)
- Bit polarity: 0 = black, 1 = white
- No runtime text rendering needed - pages display directly on e-ink
- Faster page display compared to EPUB since no parsing/rendering
required
- Memory efficient: loads one page at a time (48KB per page)
- Tested with XTC files generated from https://x4converter.rho.sh/
- Verified correct page alignment and color rendering
- Please report any issues if you test with XTC files from other
sources.
---------
Co-authored-by: Dave Allie <dave@daveallie.com>
