Android Tips & Tricks

Short presentation about my favorite tips & tricks for Android developers.

Meet.mobile Szczecin 28 September 2015

Transcript

1. Tips & Tricks Android Sebastian Świerczek
2. Tips & Tricks list #1 Gradle libraries versions #2 Android Support Annotations #3 Dependencies conflicts resolving #4 StrictMode #5 Tools Attributes
3. Gradle libraries versions #1
4. Versions for single module def libVersion = [ support : "23.0.1", supportTest: "0.4" ] dependencies { compile "com.android.support:appcompat-v7:${libVersion.support}" compile "com.android.support:recyclerview-v7:${libVersion.support}" androidTestCompile "com.android.support.test:runner:${libVersion.supportTest}" androidTestCompile "com.android.support.test:rules:${libVersion.supportTest}" } #1 Gradle libraries versions root > appModule > build.gradle > module2 > build.gradle > build.gradle
5. Versions for all modules ext { libVersion = [ support : "23.0.1", supportTest: "0.4" ] libDependencies = [ recyclerView : "com.android.support:recyclerview-v7:${libVersion.support}", appCompat : "com.android.support:appcompat-v7:${libVersion.support}", supportTestRunner : "com.android.support.test:runner:${libVersion.supportTest}", supportTestRules : "com.android.support.test:rules:${libVersion.supportTest}" ] } #1 Gradle libraries versions root > appModule > build.gradle > module2 > build.gradle > build.gradle
6. Versions for all modules dependencies { compile libDependencies.recyclerView compile libDependencies.appCompat androidTestCompile libDependencies.supportTestRunner androidTestCompile libDependencies.supportTestRules } #1 Gradle libraries versions root > appModule > build.gradle > module2 > build.gradle > build.gradle
7. Android Support Annotations #2
8. #2 Android Support Annotations Resource Type Annotations public void passStringResource(@StringRes int stringResId){...} public void passColorResource(@ColorRes int colorResId){...} public void passDrawable(@DrawableRes int drawableResId){...} public void passColorRgbInt(@ColorInt int rgbColor){...} public void passStringOrColor(@StringRes @ColorRes int stringOrColorResId){...}
9. #2 Android Support Annotations Resource Type Annotations passStringResource(R.string.app_name); passStringResource(R.color.black); passStringResource(1234);
10. #2 Android Support Annotations Resource Type Annotations passStringOrColorResource(R.string.app_name); passStringOrColorResource(android.R.color.white); passStringOrColorResource(R.drawable.ic_launcher);
11. #2 Android Support Annotations Resource Type Annotations passColorRgbInt(resources.getColor(R.color.white)); passColorRgbInt(0xFFFFFFFF); passColorRgbInt(R.color.white);
12. #2 Android Support Annotations Typedef Annotations @IntDef ({ DOWNLOAD_IDLE, DOWNLOAD_IN_PROGRESS}) public @interface DownloadStatus {} public static final int DOWNLOAD_IDLE = 0; public static final int DOWNLOAD_IN_PROGRESS = 1;
13. #2 Android Support Annotations Typedef Annotations public void setDownloadStatus(@DownloadStatus int status) {...}
14. #2 Android Support Annotations Typedef Annotations setDownloadStatus(DOWNLOAD_IDLE); setDownloadStatus(DOWNLOAD_IN_PROGRESS); setDownloadStatus(1234);
15. Dependencies conflicts resolving #3
16. #3 Dependencies conflicts resolving Google Play Services dependencies conflict Error:Execution failed for task ':app:processDebugResources'. > Error: more than one library with package name 'com.google.android.gms' You can temporarily disable this error with android.enforceUniquePackageName=false However, this is temporary and will be enforced in 1.0
17. #3 Dependencies conflicts resolving Dependencies compile 'com.google.android.gms:play-services-maps:8.1.0' compile 'co.realtime:messaging-android:2.1.52'
18. #3 Dependencies conflicts resolving androidDependencies task to the rescue ./gradlew androidDependencies
19. #3 Dependencies conflicts resolving androidDependencies task to the rescue +--- com.google.android.gms:play-services-maps:8.1.0 | \--- com.google.android.gms:play-services-base:8.1.0 | \--- com.google.android.gms:play-services-basement:8.1.0 | \--- com.android.support:support-v4:23.0.1 | \--- LOCAL: internal_impl-23.0.1.jar +--- co.realtime:messaging-android:2.1.52 | +--- LOCAL: json_simple-1.1.jar | +--- LOCAL: httpcore-4.2.4.jar | +--- com.google.android.gms:play-services:6.1.71
20. #3 Dependencies conflicts resolving Fix the issue compile 'com.google.android.gms:play-services:8.1.0' compile 'co.realtime:messaging-android:2.1.52'
21. StrictMode #4
22. #4 StrictMode Detect UI Thread operations if (DEBUG) { StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder() .detectAll() .penaltyLog() .build()); StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder() .detectAll() .penaltyLog() .build()); }
23. #4 StrictMode Example output StrictMode policy violation; ~duration=6193 ms: android.os.StrictMode$StrictModeDiskReadViolation: policy=31 violation=2 at (…) onReadFromDisk(StrictMode.java:1137) (…) at (…) (MainActivity.java:36)
24. Tools Attributes #5
25. #5 Tools Attributes Tools Layout Attributes View in designer. <FrameLayout (...) xmlns:tools="http://schemas.android.com/tools"> <TextView (...) android:text="@string/hello_world" tools:text="@string/long_text" /> <Button android:id="@+id/youCanSeeMeAtRuntime"(...) android:visibility="visible" tools:visibility="gone" /> </FrameLayout>
26. #5 Tools Attributes Tools Layout Attributes View at runtime.
27. #5 Tools Attributes Tools Layout Pointer <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent"> <fragment android:id="@+id/my_fragment" android:name="com.example.user.exampleapp.MyFragment" android:layout_width="match_parent" android:layout_height="match_parent" tools:layout="@layout/my_fragment_layout" /> </FrameLayout>
28. #5 Tools Attributes Tools Layout Pointer Without: With: