I'm new to android studio and I want to animate an imageButton with a sequential animation set. The animation set (animation_boutons.xml)is in res/anim.
I've tried with animationSet in java but the app crashed every time I launched the emulator.
I've spent a long time looking for a solution. I hope someone can help me !
I apologize if it's something obvious.
java code:
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
configureCodeurBouton();
}
private void configureCodeurBouton() {
ImageButton boutonCodeur = findViewById(R.id.boutoncodeur);
Animation animBoutons = AnimationUtils.loadAnimation(getApplicationContext(), R.anim.anim_boutons);
animBoutons.setRepeatCount(Animation.INFINITE);
boutonCodeur.setAnimation(animBoutons);
boutonCodeur.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startActivity(new Intent(MainActivity.this, codeur.class));
}
});
}
}
xml code:
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:shareInterpolator="true"
android:fillAfter="true">
<rotate
android:fromDegrees="0"
android:toDegrees="20"
android:pivotX="50%"
android:pivotY="50%"
android:startOffset="0"
android:duration="1000"
/>
<rotate
android:startOffset="1000"
android:fromDegrees="20"
android:toDegrees="-20"
android:pivotX="50%"
android:pivotY="50%"
android:duration="2000"
/>
<rotate
android:fromDegrees="-20"
android:toDegrees="0"
android:pivotX="50%"
android:pivotY="50%"
android:startOffset="3000"
android:duration="1000"
/>
</set>
Also, Vedprakash Wagh give me the advice to try animBoutons.setRepeatCount(Animation.INFINITE) but it has no effect).
Your app is crashing every time because you're trying to find your ImageButton when the class is created first, and not after the layout is set.
You're getting NullPointerException, as there is no ImageButton with id R.id.boutoncodeur in your View hierarchy when you're trying to find it.
You need to find your ImageView AFTER it is available in your View hierarchy i.e. after your setContentView();
You can either do this:
Remove your second line
ImageButton boutonCodeur = findViewById(R.id.boutoncodeur);
as you've already found your ImageView in your configureCodeurButton() function.
Or, you can keep one class variable of ImageView, and make findViewById call after setContentView like below.
public class MainActivity extends AppCompatActivity {
ImageButton boutonCodeur;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
boutonCodeur = findViewById(R.id.boutoncodeur);
configureCodeurBouton();
}
private void configureCodeurBouton() {
Animation animBoutons = AnimationUtils.loadAnimation(getApplicationContext(), R.anim.anim_boutons);
boutonCodeur.setAnimation(animBoutons);
boutonCodeur.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startActivity(new Intent(MainActivity.this, codeur.class));
}
});
}
}
You can learn more about NullPointerException here. Also, learn how to read the errors from tutorials that are available. Or, simply open the logcat tab in Android Studio when the error occurs to know what Error you're getting.
To make your animation run infinitely, you can add this in your code.
animation.setRepeatCount(Animation.INFINITE)
I just had to change the whole xml anim_boutons file so I have only one animation and not three rotate animations. the repeatMode line says to repeat the animation backwards at each repeat. This gives the expected effect.
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:shareInterpolator="true"
android:fillAfter="true">
<rotate
android:fromDegrees="-20"
android:toDegrees="20"
android:pivotX="50%"
android:pivotY="50%"
android:startOffset="0"
android:duration="1000"
android:repeatCount="infinite"
android:repeatMode="reverse"
/>
</set>
Related
I have anim file
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="60000"
android:fillAfter="true"
android:interpolator="#android:anim/linear_interpolator"
android:shareInterpolator="false" >
<rotate
android:startOffset="0"
android:fromDegrees="0"
android:pivotX="50%"
android:pivotY="50%"
android:toDegrees="360" />
</set>
and I want animation to start immediately. But is starts after 2-3 sec delay. What can be the reason?
Its working properly in my code. So there are no error in XML. Please check your Java. My Java code is:
void startAnim() {
view.clearAnimation();
Animation anim= AnimationUtils.loadAnimation(MainActivity.this, R.anim.anim);
view.startAnimation(anim);
}
private ImageView logo;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
logo=(ImageView)findViewById(R.id.logo);
Animation myanim = AnimationUtils.loadAnimation(this,R.anim.anim);
logo.startAnimation(myanim);
}
I'd like to apply 2 alternate rotation animations to a View. Each rotation should start after the click on the same View.
The result I'm looking for is:
the user clicks on the View and it rotates from 0° to 135°
the user clicks again on the View and it rotates from 135° to 0° (to the initial state)
The problem is that, when the user performs the second click, the Button resets to the initial aspect before starting the animation correctly.
I'm targeting Android APIs<11 so I'm using the startAnimation() method. The animations are applied to a Button view defined as follows:
<Button
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
The animations are the following
rotate_cw.xml (0° to 135° rotation):
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:fillAfter="true">
<rotate
android:duration="300"
android:fromDegrees="0"
android:pivotX="50%"
android:pivotY="50%"
android:toDegrees="135" />
</set>
rotate_ccw.xml (135° to 0° rotation):
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<rotate
android:duration="300"
android:fromDegrees="135"
android:pivotX="50%"
android:pivotY="50%"
android:toDegrees="0"/>
</set>
The animations are then applied in this way, where flag is a boolean global variable:
Button b = (Button) findViewById(R.id.button);
b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (flag) {
Animation a = AnimationUtils.loadAnimation(this, R.anim.rotate_cw);
b.startAnimation(a);
} else {
Animation a = AnimationUtils.loadAnimation(this, R.anim.rotate_ccw);
b.startAnimation(a);
}
flag = !flag;
}
});
Am I missing anything?
Thanks in advance for your help.
here is xml file：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="150dp"
android:layout_height="match_parent">
<Button
android:id="#+id/textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
here is java code
private Button text;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
text = (Button)findViewById(R.id.textview);
text.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
text.startAnimation(getScaleAnimation());
}
});
}
private ScaleAnimation getScaleAnimation(){
ScaleAnimation animation = new ScaleAnimation(1f,1.2f,1f,1.2f,Animation.RELATIVE_TO_SELF,0.5f,Animation.RELATIVE_TO_SELF,0.5f);
animation.setDuration(1000);
animation.setFillAfter(true);
return animation;
}
I am performing a simple ScaleAnimation on a Button.Is there any way I can get the animated view?
Just open anim folder inside res folder. Create an xml file. Then you need to create set tag. Inside of it, you can create scale tag.
Here is an example:
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:interpolator="#android:anim/accelerate_interpolator">
<scale
android:fromXScale="0.5"
android:toXScale="2"
android:fromYScale="0.5"
android:toYScale="2"
android:pivotX="50%"
android:pivotY="50%"
android:duration="5000"
/>
</set>
Note: do not forget to include xmlns:android declaration.
Now, inside of onCreate method or wherever you want, just put following. I am animating(scaling) a button itself when it is clicked:
Button but = (Button) findViewById(R.id.button1);
but.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Animation anim = AnimationUtils.loadAnimation(AnimationActivity.this, R.anim.animation);
but.startAnimation(anim);
}
});
EDIT:
in case you want to rotate it while scaling, you can put following inside of the xml file:
<rotate
android:fromDegrees="0"
android:toDegrees="360"
android:pivotX="50%"
android:pivotY="50%"
android:duration="5000"
/>
Hope this helps.
Use this way
Create an xml inside /res/anim folder and put the below code into it.
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="schemas.android.com/apk/res/android"
android:interpolator="#android:anim/linear_interpolator">
<scale android:fromXScale="0.0" android:fromYScale="0.0"
android:toXScale="1.0" android:toYScale="1.0"
android:duration="700" android:fillBefore="false" />
</set>
Place the below code inside the java file:
Animation scaleAnimation
= AnimationUtils.loadAnimation(this, R.anim.logoanimation);
Btn.startAnimation(scaleAnimation);
logoanimation is the name of my animation xml file.
for more refer this tutorial
I have different screen to work in an android application.
I'm using ViewFlipper for this.
I decided to used different class for different view children
public main extends Activity{
{
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.sign_in);
ViewFlipper viewFlipper = (ViewFlipper) findViewById(R.id.viewFlipper);
HomeScreen s = new HomeScreen(getApplicationContext(), getCurrentFocus(), viewFlipper);
}
}
and this the Homescreen class is :-
public class HomeScreen {
private Button signIn;
private Button createAccount;
private View v;
private Context context;
private ViewFlipper viewflipper;
public HomeScreen(Context context,View v,ViewFlipper viewflipper ) {
this.v=v;
this.context = context;
this.viewflipper = viewflipper;
signIn = (Button) v.findViewById(R.id.button_sign_in_homeScreen);
createAccount = (Button)v.findViewById(R.id.button_createAccount_homeScreen);
signIn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
viewflipper.setDisplayedChild(1);
}
});
}
but is shows run exception
java.lang.RuntimeException: Unable to start activity ComponentInfo
Can anyone please help me
is getCurrentFocus() is the correct way to get the view?
What i try to implement is
I need to use different class for defining, listening the controls of each child of view flipper
In the above example HomeScreen is one of my the child screen of view flipper
But the line v.findViewById is showing error i think that getCurrentFocus() is not the correct way to sent the view
I don't know weather i'm moving in the correct way? When i define and listen all the controls of all children of viewflipper in the Class where i define that viewflpper, that class become very big. That made me to think so..
Thanks...
U can perfrom animation using Intent to:
Step1: create anim folder under res directory in ur project.
Step2: create an slideleft.xml file
Step3: type the following code in that file
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:interpolator="#android:anim/accelerate_interpolator">
<translate android:fromXDelta="100%p" android:toXDelta="0"
android:duration="400" />
</set>
step 4: similarly create slideright.xml
step5: use the above code, but change the following
<translate android:fromXDelta="-100%p" android:toXDelta="0"
android:duration="400" />
step 6:
target.startAnimation(AnimationUtils.loadAnimation(HomeScreen.this, R.anim.slide_left));
perfroming fadein operation, just add the following code in fadein.xml file
<?xml version="1.0" encoding="utf-8"?>
<alpha xmlns:android="http://schemas.android.com/apk/res/android"
android:interpolator="#android:anim/accelerate_interpolator"
android:fromAlpha="0.0" android:toAlpha="1.0"
android:duration="300" />
similarly for fade out too
<?xml version="1.0" encoding="UTF-8"?>
<alpha xmlns:android="http://schemas.android.com/apk/res/android"
android:interpolator="#android:anim/accelerate_interpolator"
android:fromAlpha="1.0" android:toAlpha="0.0"
android:duration="300" />
I still try different basics with android, and now I'm stuck with animation. I'm trying to implement a simple animation. I've defined animation in xml file like this:
alpha android:interpolator="#android:anim/accelerate_interpolator" android:fromAlpha="0.0" android:toAlpha="1.0" duration="3000" repeatCount="infinite"
In my main view group I have an ImageView defined like this:
<ImageView android:id="#+id/someb" android:src="#drawable/earth_normal" android:layout_width="wrap_content" android:layout_height="wrap_content" android:padding="5dip"/>
And this is from my starting activity class:
public class Ohayou extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ImageView earth = (ImageView)findViewById(R.id.someb);
Animation earthFadeInAnimation = AnimationUtils.loadAnimation(this, R.anim.fade_in);
earth.startAnimation(earthFadeInAnimation);
}
It finds ImageView successfuly and creates animation. but when I start emulator ImageView just shows the original src image, not an animation. What am I doing wrong?
Thanks
I see you have a correct code but I have doubt in your \anim\fade_in.xml, so try this
<?xml version="1.0" encoding="UTF-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<alpha android:fromAlpha="0.0" android:toAlpha="1.0" android:interpolator="#android:anim/accelerate_interpolator"
android:duration="3000" android:repeatCount="infinite"/>
</set>