Basic and scientific android calculator app with unit testing all written using Kotlin
- Uses EvalEx
- EvalEx is a handy expression evaluator for Java, that allows to evaluate simple mathematical and boolean expressions
- Finding this tool was a big relief because it uses BigDecimal precision. I was using exp4j, but the double precision led to floating point rounding errors.
- Calculations based on text input. Uses Reverse Polish Notation (RPN).
- Has two different layouts for portrait and landscape. I had a hard time finding code examples on the internet that had both these features
- Attempting to include unit testing because it was very difficult to find good articles explaining how to do these. (still in development)
- Windows 10
- Kotlin code for back-end
- Android Studio 3.4.1
- target SDK 24
- min/max SDK 21/29
- Packages added to build.gradle listed in the Wiki (still in development)
- layout designed checked on:
- Nexus 5, xxhdpi
- Nexus 5X, 420dpi
- Pixel 2, 420dpi
- Nexus 7, tvhdpi
- Used the following virtual devices in the Android Studio Emulator
| Name | Resolution | API | Target |
|---|---|---|---|
| Nexus 5X | 1080 x 1920: 420dpi | 24 | Android 7.0 |
| Nexus 5 | 1080 x 1920: xxhdpi | 21 | Android 5.0 |
| Pixel 2 | 1080 x 1920: 420dpi | 24 | Android 7.0 |
| Pixel 2 | 1080 x 1920: 420dpi | 29 | Android 9.+ |