Schaumamal (pronounced SHAU-muh-MAAL) is a lightweight, cross-platform layout inspector for Android devices. It's meant to be a successor to the old and retired UiAutomatorViewer. Schaumamal's central features are its dump history and multi-display support. Its fresh UI and better UX are also a plus.
Tip
Go straight to the Known problems section if you're encountering problems with Schaumamal.
Android Studio already has a powerful Layout Inspector. Why would anyone use this instead? There are two main reasons.
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The Android Studio Layout Inspector requires a debuggable process to inspect the application layout. But that isn't always available or easy to produce. For example, QA engineers that write Appium tests for Android applications/systems greatly profit from a layout inspector that lifts this requirement.
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While the Android Studio Layout Inspector works wonderfully with standard Android emulator images, some custom images create difficulties and sometimes completely prohibit it from working. From my experience, Schaumamal is not affected by this.
As such, Schaumamal can be a useful addition to the toolbox of both an Android QA engineer and an Android developer.
The application has a simple UI that should look familiar to users of other layout inspectors. At the center of the application is the screenshot of the currently selected display.
Starting from the top left, the most important element is the red dump button. It is followed by some information about the current dump and a button that opens the dump history pane. After that, there's a display control pill with two buttons for switching between displays.
The dump history pane displays the last 15 dumps. Click on any of them to inspect it again.
In the bottom left corner, there are three buttons for screenshot control: fit-to-screen, enlarge and shrink.
When a new release is available on GitHub, an animated update icon appears over the screenshot control buttons. Clicking it opens a popup with a link to the release.
On the right side, there are two panes. The upper pane shows the UI element tree for the currently selected display. The lower pane shows all properties for the selected UI element. Click on the value of any property to copy its text.
Under the hood, Schaumamal uses the uiautomator dump --windows command, which dumps the display contents into an XML file.
The screenshots are taken using the screencap command. A confusing algorithm then matches the screenshots to the
contents of the XML dump and out comes the usable information displayed on your screen.
Thus, really the only requirement is an ADB connection to an Android device.
Ideally, this list would not be needed. But currently, you might encounter the following problems:
Sometimes, when using Schaumamal while an Appium server is running, the ADB connection fails.
The most reliable solution currently is to temporarily stop the Appium server before dumping the screen content with Schaumamal. After that, the Appium server can be started again. It is annoying, but I have found no better solution as of now.
Although it happens extremely rarely, sometimes the files that Schaumamal uses to store the dump information
(screenshots, XML files and some metadata) are corrupt. The result is an immediate failure when launching the
application; the error message would most likely be Failed to launch JVM.
Caution
Proceed with caution. Incorrectly following the next instructions can lead to all Schaumamal data (dumps, settings, etc.) being lost!
To solve this problem, first look for the directory where Schaumamal stores its application data (settings, dumps, etc.):
- on macOS:
~/Library/Application Support/Schaumamal, - on Windows:
~/AppData/Local/Schaumamal, - on Linux:
~/.schaumamal.
Now back up the directory (e.g., copy and paste to some secure location) and then delete it. This will force Schaumamal to recreate the file structure, which removes the problem.
On macOS, the application window can only be dragged if one first clicks on the top bar, then waits a short moment and only then drags the window. This comes from a bug in the JetBrains Jewel library. I am still waiting for a fix. 😅
There are a lot of planned features in sight. They include:
- search functionality for the UI element tree,
- a settings pane (for customizing stuff like max. dump history entries and the screenshot matching algorithm),
- making the UI element tree nodes collapsable,
- and much more!
Do not hesitate to create a GitHub Issue if you encounter any bugs or would like to make a feature request. All feedback is highly appreciated! Or...
If you would like to fix a problem or add a feature yourself, you are welcome to contribute to the project.
This is open-source, after all. I'll be happy to help where needed