Programming stuff to remember 2015 Jan

Backup android (useful links)

These are the pages what I used when I migrated my data to a new phone.

https://dbremes.wordpress.com/2013/02/11/how-to-get-a-backup-of-your-android-applications-database-in-windows/
http://www.kossboss.com/android---adb-backups---adb-extractor-abe---extracting-adbs-with-openssl
http://forum.xda-developers.com/showthread.php?t=2011811
http://mobility.forumsee.com/a/m/s/p12-9522-0182226--how-extract-create-edit-android-adb-backups.html

Indeterminate progressbar with rounded corners

The build in android progressbar can be customised to use different drawables, but than the corners would be sharp. Our designer need it to be rounded. My solution is flexible enough that it can be cropped to any shape.

This is how I did it (essentially creating a custom Drawable from program code).

It gets a Drawable, tiles it (repeating it) and crops it to a shape that was provided by the Callable. It handles AnimationDrawable also: creates a similar AnimationDrawable tiling and cropping each frame. For the clip shape I had to use Callable - which is essentially a factory - because a new ShapeDrawable has to be created for each animation frame.  The inner class EquallyRoundCornerRect can be used for the most common scenario: equal round corner.

/**
 * It gets a {@link android.graphics.drawable.Drawable}, tiles it (repeating it) and crops it to a shape that was provided by the
 * {@link java.util.concurrent.Callable}. It handles {@link android.graphics.drawable.AnimationDrawable} also: creates a similar
 * {@link android.graphics.drawable.AnimationDrawable} tiling and cropping each frame. For the clip shape I had to use
 * {@link java.util.concurrent.Callable} - which is essentially a factory - because a new {@link android.graphics.drawable.ShapeDrawable}
 * has to be created for each animation frame.
 * The inner class {@link EquallyRoundCornerRect} can be used for the most common scenario: equal round corner.
 */
public class TiledClippedDrawable {

    public static Drawable createFrom(final Drawable originalDrawable, final Callable<ShapeDrawable> clipShape) {
        return tileifyIndeterminate(originalDrawable, clipShape);
    }

    private static Drawable tileify(Drawable drawable, final Callable<ShapeDrawable> clipShape) {
        final Bitmap tileBitmap = ((BitmapDrawable) drawable).getBitmap();
        try {
            final ShapeDrawable shapeDrawable = clipShape.call();

            final BitmapShader bitmapShader = new BitmapShader(tileBitmap,
                    Shader.TileMode.REPEAT, Shader.TileMode.REPEAT);
            shapeDrawable.getPaint().setShader(bitmapShader);

            return new ClipDrawable(shapeDrawable, Gravity.LEFT, ClipDrawable.HORIZONTAL);
        }
        catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    private static Drawable tileifyIndeterminate(Drawable drawable, final Callable<ShapeDrawable> clipShape) {
        if (drawable instanceof AnimationDrawable) {
            AnimationDrawable background = (AnimationDrawable) drawable;
            final int N = background.getNumberOfFrames();
            AnimationDrawable newBg = new AnimationDrawable();
            newBg.setOneShot(background.isOneShot());

            for (int i = 0; i < N; i++) {
                Drawable frame = tileify(background.getFrame(i), clipShape);
                frame.setLevel(10000);
                newBg.addFrame(frame, background.getDuration(i));
            }
            newBg.setLevel(10000);
            drawable = newBg;
            return drawable;
        }
        return tileify(drawable, clipShape);
    }

    public static class EquallyRoundCornerRect implements Callable<ShapeDrawable> {
        private final int cornerRadiusPixel;

        public EquallyRoundCornerRect(final int cornerRadiusPixel) {
            this.cornerRadiusPixel = cornerRadiusPixel;
        }

        @Override
        public ShapeDrawable call() throws Exception {
            final float[] roundedCorners = new float[] {cornerRadiusPixel, cornerRadiusPixel, cornerRadiusPixel, cornerRadiusPixel,
                    cornerRadiusPixel, cornerRadiusPixel, cornerRadiusPixel, cornerRadiusPixel};
            return new ShapeDrawable(new RoundRectShape(roundedCorners, null, null));
        }
    }
}

And this is how it can be used:

final int cornerRadius = getResources().getDimensionPixelOffset(R.dimen.progressbar_corner_radius);
final Drawable originalDrawable = getResources().getDrawable(R.drawable.progress_bar_indeterminate_horizontal);
final Drawable roundedAnimation = TiledClippedDrawable.createFrom(originalDrawable, new TiledClippedDrawable.EquallyRoundCornerRect(cornerRadius));
unpackingSpinner = (ProgressBar) backView.findViewById(R.id.gallery_item_unpacking_spinner);
unpackingSpinner.setIndeterminateDrawable(roundedAnimation);

Here the R.dimen.progressbar_corner_radius is a number, and the R.drawable.progress_bar_indeterminate_horizontal is an animationlist. Each of those install_progressbar_indeterminate1 images contain only a fragment, because they will be tiled anyway.

<animation-list
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:oneshot="false">
    <item android:drawable="@drawable/install_progressbar_indeterminate1" android:duration="200" />
    <item android:drawable="@drawable/install_progressbar_indeterminate2" android:duration="200" />
    <item android:drawable="@drawable/install_progressbar_indeterminate3" android:duration="200" />
</animation-list>

Maven stuff

First off, here is a page that contains some global maven properties. Some best practices.

Deploy lib to local maven repo

mvn install:install-file -Dfile=target/eyjafjalla.apklib -DgroupId=com.example -DartifactId=eyjafjalla -Dversion=1 -Dpackaging=apklib

Running maven with profiles:

mvn groupId:artifactId:goal -P profile-1,profile-2

Deactivating profiles:

mvn groupId:artifactId:goal -P !profile-1,!profile-2

This can be used to deactivate profiles marked as activeByDefault or profiles that would otherwise be activated through their activation config.

Available properties:

mvn help:system

By default run all tests, but this can be disabled:

<profile>
    <id>by_default_run_all_tests</id>
    <activation>
        <property>
            <name>!notest</name>
        </property>
    </activation>
    <properties>
        <notest>false</notest>
    </properties>
</profile>
...
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>2.6</version>
    <configuration>
        <skip>${notest}</skip>
        <skipTests>false</skipTests>
    </configuration>
</plugin>

Run with

mvn install -Dnotest

Related stackoverflow question

Or more generic default overridable parameter:

<profile>
    <id>by_default_copy_poker_assets</id>
    <activation>
        <property>
            <name>!noassetoverwrite</name>
        </property>
    </activation>
    <properties>
        <overwrite_poker_asset>true</overwrite_poker_asset>
    </properties>
</profile>

<profile>
    <id>do_not_copy_poker_assets</id>
    <activation>
        <property>
            <name>noassetoverwrite</name>
        </property>
    </activation>
    <properties>
        <overwrite_poker_asset>false</overwrite_poker_asset>
    </properties>
</profile>

Execute shell command:

<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>exec-maven-plugin</artifactId>
    <version>1.1.1</version>
    <executions>
        <execution>
            <id>some-execution</id>
            <phase>validate</phase>
            <goals>
                <goal>exec</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
        <executable>python</executable>
        <workingDirectory>${project.basedir}/..</workingDirectory>
        <arguments>
            <argument>~/Rockaway/file_date_check/file_date_check.py</argument>
        </arguments>
    </configuration>
</plugin>

Plugin for IntelliJ to permute a list of enything

Many times I encounter the situation, where I want to reorder a list: enum values, DataSet test cases, parameters of a function, elements of a list, etc. Cut and paste is just too much effort, and extra care has to be taken to keep formatting. So I've written a small code snippet to rearrange these lists. I use IntelliJ's LivePlugin (on github) to use it quickly (but it could be converted to a full Java plugin). But unfortunatelly it handles Groovy script. Testing groovy script I find it pain in the ass, so I've created a Java barebone with test, and than converted it to Groovyscript (I myself find this approach a bit stupid, though).

How it works? If your carret is sitting in between any type of brackets, it finds the innermost it sits in. It finds the list element (text, that can contain spaces, other closed brackets, comas inside those brackets). With Ctrl+Alt+L it swaps it to the right, with Ctrl+Alt+K, it swaps it to the left. The carret moves with the item.

Known limitations. If there is an unclosed backet (syntactically incorret code), it doesn't handle it well. If the carret is not inside a backet, the behaviour is unpredicted.

The rest of the post is just source code. The Java fragment:

int start;
    int end;
    int mid;
    int midLeft;
    int midRight;
    public String doTheFlop(final String input, final int carretPos) {
        start = carretPos - 1;
        mid = carretPos;

        travelToBeginning(input);

        travelToMid(input);

        if (isRightLimiter(input.charAt(mid))) {
            return null;
        }

        midLeft = mid ;
        midRight = mid ;
        travelToMidLeft(input);

        travelToMidRight(input);

        end = midRight;
        travelToEnd(input);

        return input.substring(midRight, end) + input.substring(midLeft, midRight) + input.substring(start, midLeft);
    }

    private void travelToBeginning(final String input) {
        int groupDepth = 0;
        while (!((input.charAt(start) == ',' && groupDepth == 0)
               || (isLeftLimiter(input.charAt(start)) && groupDepth == 0))) {
            if (isRightLimiter(input.charAt(start))) {
                groupDepth++;
            }
            if (isLeftLimiter(input.charAt(start))) {
                groupDepth--;
            }
            start--;
        }
        start++;
        while (Character.isWhitespace(input.charAt(start))) {
            start++;
        }
    }

    private void travelToMid(final String input) {
        int groupDepth = 0;
        while (!((input.charAt(mid) == ',' && groupDepth == 0)
                 || (isRightLimiter(input.charAt(mid)) && groupDepth == 0))) {
            if (isLeftLimiter(input.charAt(mid))) {
                groupDepth++;
            }
            if (isRightLimiter(input.charAt(mid))) {
                groupDepth--;
            }
            mid++;
        }
    }

    private void travelToMidLeft(final String input) {
        // this currently points to a coma or bracket
        midLeft--;
        while (Character.isWhitespace(input.charAt(midLeft))) {
            midLeft--;
        }
        midLeft++;
    }

    private void travelToMidRight(final String input) {
        // this currently points to a coma or bracket
        midRight++;
        while (Character.isWhitespace(input.charAt(midRight))) {
            midRight++;
        }
    }

    private void travelToEnd(final String input) {
        int groupDepth = 0;
        while (!((input.charAt(end) == ',' && groupDepth == 0)
                 || (isRightLimiter(input.charAt(end)) && groupDepth == 0))) {
            if (isLeftLimiter(input.charAt(end))) {
                groupDepth++;
            }
            if (isRightLimiter(input.charAt(end))) {
                groupDepth--;
            }
            end++;
        }

        end--;
        while (Character.isWhitespace(input.charAt(end))) {
            end--;
        }
        end++;
    }

    private boolean isLeftLimiter(final char c) {
        return c == '(' || c == '<' || c == '[' || c == '{';
    }

    private boolean isRightLimiter(final char c) {
        return c == ')' || c == '>' || c == ']' || c == '}';
    }

Test for this:

public static class Stuff extends SimpleTestVectors {
        @Override
        protected Object[][] generateTestVectors() {
            return new Object[][] {
                    //"(  final Broad broadcast,  final  Frame   frame,final   Logger logger)"
                    //(Logger logger,    Frame< String, Integer  > frame, final   @Named ( "quickDepositStatusIntentTranslator" ) Broad broadcast)
                    {"(  ", "final Broad broadcast,  final  Frame   frame,final   Logger logger)", "final  Frame   frame,  final Broad broadcast"},  //, "(  final  Frame   frame,  final Broad broadcast,final   Logger logger)"
                    {"(  final Broad br", "oadcast,  final  Frame   frame,final   Logger logger)", "final  Frame   frame,  final Broad broadcast"},  //, "(  final  Frame   frame,  final Broad broadcast,final   Logger logger)"
                    {"(  final Broad br", "oadcast,  final  Frame   frame,final   Logger logger)", "final  Frame   frame,  final Broad broadcast"},  //, "(  final  Frame   frame,  final Broad broadcast,final   Logger logger)"
                    {"(  final Broad broadcast", ",  final  Frame   frame,final   Logger logger)", "final  Frame   frame,  final Broad broadcast"},  //, "(  final  Frame   frame,  final Broad broadcast,final   Logger logger)"
                    {"(  final Broad broadcast,", "  final  Frame   frame,final   Logger logger)", "final   Logger logger,final  Frame   frame"},  //, "(  final Broad broadcast,  final   Logger logger,final  Frame   frame)"
                    {"(  final Broad broadcast,  final  Fr", "ame   frame,final   Logger logger)", "final   Logger logger,final  Frame   frame"},  //, "(  final Broad broadcast,  final   Logger logger,final  Frame   frame)"
                    {"(  final Broad broadcast,  final  Frame   frame,final   ", "Logger logger)", null},  //, "(  final Broad broadcast,  final  Frame   frame,final   Logger logger)"

                    {"(Broad broadcast, Fr", "ame frame      , Logger logger   )", "Logger logger      , Frame frame"},  //, "(final Broad broadcast, final Logger logger      , final Frame frame   )"

                    {"(final   @", "Named ( \"quickDepositStatusIntentTranslator\" ) Broad broadcast, Frame< String, Integer  > frame, Logger logger)", "Frame< String, Integer  > frame, final   @Named ( \"quickDepositStatusIntentTranslator\" ) Broad broadcast"}, //"(Frame< String, Integer  > frame, final   @Named ( \"quickDepositStatusIntentTranslator\" ) Broad broadcast, Logger logger)"},
                    {"(final   @Named ( \"quickDepositS", "tatusIntentTranslator\" ) Broad broadcast, Frame< String, Integer  > frame, Logger logger)", null}, //"(final   @Named ( \"quickDepositStatusIntentTranslator\" ) Broad broadcast, Frame< String, Integer  > frame, Logger logger)"},
                    {"(final   @Named ( \"quickDepositStatusIntentTranslator\" ", ") Broad broadcast, Frame< String, Integer  > frame, Logger logger)", null}, //"(final   @Named ( \"quickDepositStatusIntentTranslator\" ) Broad broadcast, Frame< String, Integer  > frame, Logger logger)"},
                    {"(final   @Named ( \"quickDepositStatusIntentTranslator\" ) Broad", " broadcast, Frame< String, Integer  > frame, Logger logger)", "Frame< String, Integer  > frame, final   @Named ( \"quickDepositStatusIntentTranslator\" ) Broad broadcast"}, //"(Frame< String, Integer  > frame, final   @Named ( \"quickDepositStatusIntentTranslator\" ) Broad broadcast, Logger logger)"},
                    {"(final   @Named ( \"quickDepositStatusIntentTranslator\" ) Broad broadcast, ", "Frame< String, Integer  > frame, Logger logger)", "Logger logger, Frame< String, Integer  > frame"}, //"(final   @Named ( \"quickDepositStatusIntentTranslator\" ) Broad broadcast, Logger logger, Frame< String, Integer  > frame)"},
                    {"(final   @Named ( \"quickDepositStatusIntentTranslator\" ) Broad broadcast, Frame< S", "tring, Integer  > frame, Logger logger)", "Integer, String"}, //"(final   @Named ( \"quickDepositStatusIntentTranslator\" ) Broad broadcast, Frame< Integer, String  > frame, Logger logger)"},

                    {"(final   @Named ( \"", " foo () \" , \" bar () \" ) Broad broadcast, Frame< String, Integer  > frame, Logger logger)", "\" bar () \" , \" foo () \""}, //"(final   @Named( \" bar () \" , \" foo () \" ) Broad broadcast, Frame< String, Integer  > frame, Logger logger)""},
            };
        }
    }

    @Test
    @DataSet(testData = Stuff.class)
    public void dummy_FIXME() throws InvalidDataSetException {
        // init

        // run
        final String result = sut.doTheFlop(rule.getString(0) + rule.getString(1), rule.getString(0).length());

        // verify
        assertThat(result, equalTo(rule.getString(2)));
    }

And the final Groovyscript refined:

import com.intellij.openapi.actionSystem.AnActionEvent
import com.intellij.openapi.application.ApplicationManager
import com.intellij.openapi.editor.ScrollType
import com.intellij.openapi.editor.SelectionModel
import com.intellij.openapi.util.TextRange

import static liveplugin.PluginUtil.*
import static liveplugin.PluginUtil.showInConsole
import static liveplugin.PluginUtil.showInConsole
import static liveplugin.PluginUtil.showInConsole


registerAction("swap to right", "alt ctrl L") { AnActionEvent event ->
    def editor = currentEditorIn(event.project)
    def input = editor.getDocument().getChars()
    def caretModel = editor.getCaretModel()
    def selectionModel = editor.getSelectionModel()


    int start = caretModel.offset - 1;
    if (start < 0) return;
    int mid = start + 1;
    int end;
    int midLeft;
    int midRight;

    //travelToBeginning
    int groupDepth = 0;
    while (!((input[start] == ',' && groupDepth == 0)
            || (isLeftLimiter(input[start]) && groupDepth == 0))) {
        if (isRightLimiter(input[start])) {
            groupDepth++;
        }
        if (isLeftLimiter(input[start])) {
            groupDepth--;
        }
        start--;
    }
    // fallback to first non-whitespace char
    start++;
    while (isWhitespace(input[start])) {
        start++;
    }

    //travelToMid
    groupDepth = 0;
    while (!((input[mid] == ',' && groupDepth == 0)
            || (isRightLimiter(input[mid]) && groupDepth == 0))) {
        if (isLeftLimiter(input[mid])) {
            groupDepth++;
        }
        if (isRightLimiter(input[mid])) {
            groupDepth--;
        }
        mid++;
    }

    // this is already the last element
    if (isRightLimiter(input[mid])) {
        return;
    }

    midLeft = mid;
    midRight = mid;

    //travelToMidLeft
    // this currently points to a coma or bracket
    midLeft--;
    while (isWhitespace(input[midLeft])) {
        midLeft--;
    }
    midLeft++;

    //travelToMidRight
    // this currently points to a coma or bracket
    midRight++;
    while (isWhitespace(input[midRight])) {
        midRight++;
    }

    //travelToEnd
    end = midRight;
    groupDepth = 0;
    while (!((input[end] == ',' && groupDepth == 0)
            || (isRightLimiter(input[end]) && groupDepth == 0))) {
        if (isLeftLimiter(input[end])) {
            groupDepth++;
        }
        if (isRightLimiter(input[end])) {
            groupDepth--;
        }
        end++;
    }

    // fallback to last non-whitespace char
    end--;
    while (isWhitespace(input[end])) {
        end--;
    }
    end++;


    // do the swap
    String text = editor.document.getText(new TextRange(start, end))
    String swappedText = text.substring(midRight - start, end - start) + text.substring(midLeft - start, midRight - start) + text.substring(0, midLeft - start)

    runDocumentWriteAction(event.project, editor.document, "Swap to right a list element", "Permute plugin (mnw)") {
        editor.document.replaceString(start, end, swappedText)
    }

    caretModel.moveToOffset(end)
    editor.scrollingModel.scrollToCaret(ScrollType.MAKE_VISIBLE)
}

registerAction("swap to left", "alt ctrl K") { AnActionEvent event ->
    def editor = currentEditorIn(event.project)
    def input = editor.getDocument().getChars()
    def caretModel = editor.getCaretModel()
    def selectionModel = editor.getSelectionModel()


    int start = caretModel.offset - 1;
    if (start < 0) return;
    int carret = start;
    int lastComa;
    int mid;
    int end;
    int midLeft;
    int midRight;

    //travelToBeginning
    int groupDepth = 0;
    while (!(isLeftLimiter(input[start]) && groupDepth == 0)) {
        if (isRightLimiter(input[start])) {
            groupDepth++;
        }
        if (isLeftLimiter(input[start])) {
            groupDepth--;
        }
        start--;
    }
    lastComa = start;

    //travel backwards ToMid from start keeping track if we find coma (only the last is important)
    groupDepth = 0;
    mid = start + 1;
    while (mid <= carret) {
        if (isLeftLimiter(input[mid])) {
            groupDepth++;
        }
        if (isRightLimiter(input[mid])) {
            groupDepth--;
        }
        if (input[mid] == ',' && groupDepth == 0) {
            start = lastComa;
            lastComa = mid;
        }
        mid++;
    }

    // this is already the first element
    if (lastComa == start) {
        return;
    }

    // skip whitespaces from start
    start++;
    while (isWhitespace(input[start])) {
        start++;
    }

    midLeft = lastComa;
    midRight = lastComa;

    // skipp whitespaces around the coma
    // this currently points to a coma or bracket
    midLeft--;
    while (isWhitespace(input[midLeft])) {
        midLeft--;
    }
    midLeft++;
    // this currently points to a coma or bracket
    midRight++;
    while (isWhitespace(input[midRight])) {
        midRight++;
    }

    //travelToEnd
    end = midRight;
    groupDepth = 0;
    while (!((input[end] == ',' && groupDepth == 0)
            || (isRightLimiter(input[end]) && groupDepth == 0))) {
        if (isLeftLimiter(input[end])) {
            groupDepth++;
        }
        if (isRightLimiter(input[end])) {
            groupDepth--;
        }
        end++;
    }

    // skip ending whitespaces from end
    end--;
    while (isWhitespace(input[end])) {
        end--;
    }
    end++;


    // do the swap
    String text = editor.document.getText(new TextRange(start, end))
    String swappedText = text.substring(midRight - start, end - start) + text.substring(midLeft - start, midRight - start) + text.substring(0, midLeft - start)

    runDocumentWriteAction(event.project, editor.document, "Swap to left a list element", "Permute plugin (mnw)") {
        editor.document.replaceString(start, end, swappedText)
    }


    caretModel.moveToOffset(start + end - midRight)
    editor.scrollingModel.scrollToCaret(ScrollType.MAKE_VISIBLE)
}

private boolean isWhitespace(char charAt) {
    return charAt == " " || charAt == "\t" || charAt == "\n" || charAt == "\r" || charAt == "\f";
}

private boolean isLeftLimiter(final char c) {
    return c == '(' || c == '<' || c == '[' || c == '{';
}

private boolean isRightLimiter(final char c) {
    return c == ')' || c == '>' || c == ']' || c == '}';
}

show("permute Loaded")

Performance of intra process messages on Android

I did a small experiment to measure the performance of certain ways of calling functions on Android: direct call, call runnable through Handler, call it via a Service (and sending the result back through broadcast). Because we use the latter method quite a lot to get data from our servers or to perform some budiness logic off from the view layer.

I used this tool for the profiling: http://developer.android.com/tools/help/systrace.html

Tests performed

• Direct call of a function in a loop
  
• Message is posted (delayed with 0 delay) to a Handler. The handleMessage() posts a similar Message to itself
  
• Start Service with implicit intent, the service runs on an Executor and sends result back with global Broadcast
  
• Start Service with implicit intent, the service runs on the UI thread and sends result back with global Broadcast
  
• Start Service with explicit intent, the service runs on the UI thread and sends result back with LocalBroadcaster (v4 support lib)
  

The results (cascading 1000 times)

test name	Nexus 7	Samsung S3 (average)
direct call	52 ms	30 ms
post to handler	166 ms	87 ms
service /w executor and global broadcast	2366 ms	2700 ms
service ui thread & global broadcast	2247 ms	3200 ms
service explicit intent & local broadcast	1150 ms	1470 ms

Notes: broadcasting things actually is relatively fast, though you shouldn't use it for real time data (of course). Local broadcasting is twice as fast as global broadcast. However localBroadcaster uses a Handler internally (check source), but it resolves the Intent target. That makes the call 7-17 times slower (compared to sending message to a Handler). So if you know the target, use a handler instead. :-)

You can play around with this github repo. You can also check out an example result (Samsung Galaxy S3) in there.

Programming things to remember 2014 Aug

Screen lock and activity rotation

I wanted to know, what fragment callbacks are called during different scenarios. I tested on Nexus 7 and on Samsung Galaxy SII.
Notable things:

• inflated view doesn't have proper size till an implicitly added callback is called (ViewTreeObserver). So even during onResume the measured width and height may be 0.
  
• the difference between the home press and rotation during fragment build down is the getActivity().isChangingConfigurations() flag
  
• the difference between the home press and the back press is the onSaveInstanceState() callback. Except on samsung, which keeps the fragment, no onDestroyView+onDestroy will be called. But because of this, no onGlobalLayout is called either.
  
• on samsung, the whole activity - which is behind the lock screen - gets all the callback events during rotation. So on nexus the onStart+onResume don't run until the lock screen is unlocked. On samsung, those callbacks are called right after the screen is turned on (and before it is unlocked). Likewise the rotation events, and because the lock screen on samsung is portrait only, it will recreate the fragment; and after unlocking it will recreate the fragment again (if the activity is fixed to landscape mode).
  

Nexus 7	Samsung S2
-- start new onAttach() onCreate() savedInstanceState: null onCreateView() savedInstanceState: null onActivityCreated() savedInstanceState: null onStart() rootView.getMeasuredWidth(): 0 onResume() rootView.getMeasuredWidth(): 0 onGlobalLayout() rootView.getMeasuredHeight(): 672 -- back onPause() isChangingConfigurations: false onStop() onDestroyView() onDestroy() onDetach()	-- start new onAttach() onCreate() savedInstanceState: null onCreateView() savedInstanceState: null onActivityCreated() savedInstanceState: null onStart() rootView.getMeasuredHeight(): 0 onResume() rootView.getMeasuredHeight(): 0 onGlobalLayout() rootView.getMeasuredHeight(): 408 -- back onPause() isChangingConfigurations: false onStop() onDestroyView() onDestroy() onDetach()
-- start new onAttach() onCreate() savedInstanceState: null onCreateView() savedInstanceState: null onActivityCreated() savedInstanceState: null onStart() rootView.getMeasuredWidth(): 0 onResume() rootView.getMeasuredWidth(): 0 onGlobalLayout() rootView.getMeasuredHeight(): 672 -- replace fragment onPause() isChangingConfigurations: false onStop() onDestroyView() -- reopen fragment onCreateView() savedInstanceState: null onActivityCreated() savedInstanceState: null onStart() rootView.getMeasuredWidth(): 0 onResume() rootView.getMeasuredWidth(): 0 onGlobalLayout() rootView.getMeasuredHeight(): 672	-- start new onAttach() onCreate() savedInstanceState: null onCreateView() savedInstanceState: null onActivityCreated() savedInstanceState: null onStart() rootView.getMeasuredHeight(): 0 onResume() rootView.getMeasuredHeight(): 0 onGlobalLayout() rootView.getMeasuredHeight(): 408 -- replace fragment onPause() isChangingConfigurations: false onStop() onDestroyView() -- reopen fragment onCreateView() savedInstanceState: null onActivityCreated() savedInstanceState: null onStart() rootView.getMeasuredHeight(): 0 onResume() rootView.getMeasuredHeight(): 0 onGlobalLayout() rootView.getMeasuredHeight(): 408
-- rotate onPause() isChangingConfigurations: true onSaveInstanceState() onStop() onDestroyView() onDestroy() onDetach() onAttach() onCreate() savedInstanceState: Bundle[...] onCreateView() savedInstanceState: Bundle[...] onActivityCreated() savedInstanceState: Bundle[...] onStart() rootView.getMeasuredWidth(): 0 onResume() rootView.getMeasuredWidth(): 0 onGlobalLayout() rootView.getMeasuredHeight(): 672	-- rotate onPause() isChangingConfigurations: true onSaveInstanceState() onStop() onDestroyView() onDestroy() onDetach() onAttach() onCreate() savedInstanceState: Bundle[...] onCreateView() savedInstanceState: Bundle[...] onActivityCreated() savedInstanceState: Bundle[...] onStart() rootView.getMeasuredHeight(): 0 onResume() rootView.getMeasuredHeight(): 0 onGlobalLayout() rootView.getMeasuredHeight(): 728
-- home press onPause() isChangingConfigurations: false onSaveInstanceState() onStop() onDestroyView() onDestroy() onDetach() -- reopen onAttach() onCreate() savedInstanceState: Bundle[...] onCreateView() savedInstanceState: Bundle[...] onActivityCreated() savedInstanceState: Bundle[...] onStart() rootView.getMeasuredWidth(): 0 onResume() rootView.getMeasuredHeight(): 0 onGlobalLayout() rootView.getMeasuredHeight(): 672	-- home press onPause() isChangingConfigurations: false onSaveInstanceState() onStop() -- reopen onStart() rootView.getMeasuredHeight(): 728 onResume() rootView.getMeasuredHeight(): 728
-- lock onPause() isChangingConfigurations: false onSaveInstanceState() onStop() -- turn on -- unlock onStart() rootView.getMeasuredHeight(): 672 onResume() rootView.getMeasuredHeight(): 672	-- lock onPause() isChangingConfigurations: false onSaveInstanceState() onStop() -- turn on onStart() rootView.getMeasuredHeight(): 728 onResume() rootView.getMeasuredHeight(): 728 -- unlock
-- lock onPause() isChangingConfigurations: false onSaveInstanceState() onStop() -- turn on -- rotate onDestroyView() onDestroy() onDetach() onAttach() onCreate() savedInstanceState: Bundle[...] onCreateView() savedInstanceState: Bundle[...] onActivityCreated() savedInstanceState: Bundle[...] onStart() rootView.getMeasuredHeight(): 0 onResume() rootView.getMeasuredHeight(): 0 onPause() isChangingConfigurations: false onGlobalLayout() rootView.getMeasuredHeight(): 1141 -- unlock onResume() rootView.getMeasuredHeight(): 1141	-- lock (from landscape) onPause() isChangingConfigurations: false onSaveInstanceState() onStop() onDestroyView() onDestroy() onDetach() onAttach() onCreate() savedInstanceState: Bundle[...] onCreateView() savedInstanceState: Bundle[...] onActivityCreated() savedInstanceState: Bundle[...] onStart() rootView.getMeasuredHeight(): 0 onResume() rootView.getMeasuredHeight(): 0 onPause() isChangingConfigurations: false onGlobalLayout() rootView.getMeasuredHeight(): 728 -- turn on onResume() rootView.getMeasuredHeight(): 728 -- unlock onPause() isChangingConfigurations: true onSaveInstanceState() onStop() onDestroyView() onDestroy() onDetach() onAttach() onCreate() savedInstanceState: Bundle[...] onCreateView() savedInstanceState: Bundle[...] onActivityCreated() savedInstanceState: Bundle[...] onStart() rootView.getMeasuredHeight(): 0 onResume() rootView.getMeasuredHeight(): 0 onGlobalLayout() rootView.getMeasuredHeight(): 408

Programming things to remember 2014 Febr

Generic method for enums

For some reason (by the time, I'm writing this post, I've already forgotten) I created a class, that can extract an enum from an android Bundle (basically a Map of stuffs, in this case the stuff is String). I think the reason was to make this kind of operation easy. All the null checks are in one place, and it requires 2 lines of code to extract any enum from a bundle.

public class EnumFromBundleExtractor<T extends Enum<T>> {
    @Nonnull
    public T getValueFrom(Bundle savedInstanceState, @Nonnull String key, @Nonnull T defaultValue) {
        Preconditions.checkNotNull(key);
        Preconditions.checkNotNull(defaultValue);
        
        if (savedInstanceState == null) {
            return defaultValue;
        }
        
        final String bundledValueAsString = savedInstanceState.getString(key);
        if (bundledValueAsString == null) {
            return defaultValue;
        }
        
        try {
            return Enum.valueOf(defaultValue.getDeclaringClass(), bundledValueAsString);
        } catch (IllegalArgumentException iae) {
            return defaultValue;
        }
    }
}

Usage (VisualState is an enum):

final EnumFromBundleExtractor visualStateExtractor = new EnumFromBundleExtractor();
final VisualState visualState = visualStateExtractor.getValueFrom(savedInstanceState, BUNDLE_VISUAL_STATE_AS_ORDINAL, VisualState.INITIAL);