Develop Reference

Android: LinearLayout slide off screen animation

I have two layouts (green on top, red on bottom) in a vertical LinearLayout (parent) looking similar to this:
.
When focus goes from the green to red, I would like the green to slide up off the screen and have the red simultaneously slide up with it and fill the whole screen. And when focus moves from red back up I want the green to slide back into the screen and return to the original configuration. I have tried looking at many other questions but none have had the solution I need. I tried just changing visibility between gone and visible but I want it to be a smooth animation. I've tried using parentLayout.animate().translationY(greenLayout.getHeight()) on the outer LinearLayout and that does give the animation I want but then the red does not expand to fill the screen, like this:
.
I know this question is similar to this one but that question is really old and only had one answer which didn't work for me.

My solution has a lot of different pieces, so I'll start with the full XML and java code, and then talk about the important bits:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<View
android:id="#+id/green"
android:layout_width="match_parent"
android:layout_height="100dp"
android:background="#0f0" />
<View
android:id="#+id/red"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:background="#f00"/>
</LinearLayout>
In the XML, the only really important part is that the red view uses a height of 0dp and weight of 1. This means it takes up all extra vertical space, which will be important when we get rid of the green view.
public class MainActivity extends AppCompatActivity {
private int originalHeight;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final View green = findViewById(R.id.green);
final View red = findViewById(R.id.red);
green.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
green.getViewTreeObserver().removeGlobalOnLayoutListener(this);
originalHeight = green.getHeight();
}
});
green.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
animateHeightOfView(green, originalHeight, 0);
}
});
red.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
animateHeightOfView(green, 0, originalHeight);
}
});
}
private void animateHeightOfView(final View view, int start, int end) {
ValueAnimator animator = ValueAnimator.ofInt(start, end);
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
int height = (int) valueAnimator.getAnimatedValue();
ViewGroup.LayoutParams params = view.getLayoutParams();
params.height = height;
view.setLayoutParams(params);
}
});
animator.start();
}
}
In the Java, the two main parts are the ViewTreeObserver.OnGlobalLayoutListener and the animateHeightOfView() method.
The OnGlobalLayoutListener exists to capture the green view's original height. We have to use a listener to do this instead of just writing originalHeight = green.getHeight() inside onCreate() because the green view isn't actually laid out at that point, so getHeight() would return 0 if we tried that.
The animateHeightOfView() method leverages the ValueAnimator class to animate the height of whatever view you pass to it. Since there's no direct setter for a view's height, we can't use simpler methods like .animate(). We set up the ValueAnimator to produce int values on every frame, and then we use a ValueAnimator.AnimatorUpdateListener to modify the view's LayoutParams to set the height.
Feel free to play with it. I'm using click listeners to trigger the animation, and you mentioned focus, but you should be able to call animateHeightOfView() in a different way if it suits you.

"Inteligent" resize on layout?

I'm having an issue working with layouts, I've a linear layout (could be a relative layout or a table layout) which will contain an undefined number of buttons when the activity is loaded. This means, the quantity of buttons will be determined when the activity is being created. The thing is, I'm trying to fit them all in one line (with a center gravity) without changing each buttons' width UNTIL one of them reaches the margin of the screen. In other words, I want the buttons JUST to resize when at least one of them reaches the margin of the screen. That is because, I can't determine the space they're going to use because they are not created.
My actual linear layout:
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="40dp"
android:id="#+id/linearLayout_1"
android:layout_above="#+id/linearLayout_2"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginBottom="30dp"
android:orientation="horizontal"
android:gravity="center"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true">
</LinearLayout>
Piece of code that creates the buttons:
protected void hacerVisiblesRespuesta(){
ViewGroup linearLayout = (ViewGroup) findViewById(R.id.linearLayout);
assert linearLayout != null;
int height = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,40, getResources().getDisplayMetrics());
for(int i = 0; i < longuitudPalabra; i++){
String boton = "btn_rsp" + Integer.toString(i+1);
Button bt = new Button(this);
bt.setText("");
bt.setId(getResourceId(boton,"id",getPackageName()));
bt.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT
, height
, 1.0f));
bt.setTextColor(Color.BLACK);
bt.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
clickBotonRespuesta(v);
}
});
bt.setVisibility(View.VISIBLE);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
bt.setBackground(getDrawable(R.drawable.bgbtnrsp));
}else{
//bt.setBackgroundDrawable(getDrawable(R.drawable.bgbtnrsp));
}
bt.setTextSize(20);
Typeface typeFace= Typeface.createFromAsset(getAssets(),"fonts/Montserrat-Regular.ttf");
bt.setTypeface(typeFace);
linearLayout.addView(bt);
}
}
I've tried many things, one of them was to make the buttons' width variable with weight property. The thing is if there are a small quantity of buttons, lets say 4, their width ended up enormous. Is there any way to achieve this through code? Thanks.

have you tried this?
button.setLayoutParams (new LayoutParams(50, LayoutParams.WRAP_CONTENT)

Semi transparent Instruction activity in android

I want to display instruction activity when user opens the app for the first time. I am using shared preference for that. Whatever I am doing so far is working. But I think my way of achieving this is not right.
What I am following:
I am drawing a transparent instruction image(with instructions) in photoshop.
Checking if user is opening that page for the first time(using shared preference).
Displaying that particular image in an activity with translucent theme
private void showFrontPageGuideIfFirstTime(){
if(!prefKeeper.getBoolean(PreferenceKey.FRONT_GUIDE)){
Intent intent = new Intent(this, ShowGuide.class);
intent.putExtra(BACKGROUND_KEY, R.drawable.front_page_png);
this.startActivity(intent);
prefKeeper.putBoolean(PreferenceKey.FRONT_GUIDE, true);
}
}
And my instruction page looks something like(made in photoshop):
The Instruction Image
But I think by this way it would not work in all smart phone screens.
Where am I wrong, and what would be the best way of doing this?

Implementation as below
layout.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
android:id="#+id/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"
tools:context="in.excogitation.example_mvptdd.MainActivity">
<!-- Include your layout here-->
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Hello World!"/>
</FrameLayout>
In your activity.java
public class MainActivity extends AppCompatActivity {
FrameLayout frameLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Parent FrameLayout
frameLayout = (FrameLayout) findViewById(R.id.framelayout);
// Dynamically create a relativelayout which will be appended to framelayout
final RelativeLayout relativeLayout = new RelativeLayout(getApplicationContext());
relativeLayout.setLayoutParams(new RelativeLayout.LayoutParams(ViewGroup.LayoutParams
.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
relativeLayout.setBackgroundColor(Color.DKGRAY);
relativeLayout.setAlpha(0.7f);
relativeLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// remove the whole relativelayout on click
frameLayout.removeView(relativeLayout);
}
});
RelativeLayout.LayoutParams params;
// Place 1st 30x40 ImageView at (50,60) coordinates
params = new RelativeLayout.LayoutParams(100, 100);
params.leftMargin = 20;
params.topMargin = 50;
final ImageView imageView1 = new ImageView(getApplicationContext());
imageView1.setImageDrawable(getResources().getDrawable(R.drawable.ic_action_star));
// Add 1st imageview to relative layout
relativeLayout.addView(imageView1, params);
// Place 2nd 30x40 ImageView at (100,60) coordinates
params = new RelativeLayout.LayoutParams(120, 120);
params.leftMargin = 800;
params.topMargin = 450;
final ImageView imageView2 = new ImageView(getApplicationContext());
imageView2.setImageDrawable(getResources().getDrawable(R.drawable.ic_action_star));
// Add 2nd imageview to relative layout
relativeLayout.addView(imageView2, params);
// finally add it ot the framelayout
frameLayout.addView(relativeLayout);
}
}
Ofcourse you should modify this code with your own images and colors and interactions. Its just a simple working version that is better than loading a whole image upfront when you all you want is smaller helper images on a translucent background for the instructions.
Also you in this way you make things more Android-ish and editable. You can add more children to the relative layout like a textview to include instructions.
Screenshot on load of app and hence the relative layout as an overlay.
Screenshot on click/touch , the relative layout is removed.

Correctly animating an Android ImageView (possibly using a Matrix)

So, I have a Layout that contains a Button and an ImageView. When you press the button the ImageView should slide out from the button like I just pulled down a rolldown curtain (bushing other views below it down). Basically what the image below show. When you press the button again the ImageView should, unlike the gif, smoothly animates up again.
.
Using this SO question I've managed to animate the height from 0 to full size but in the wrong direction. I set the scaleType to "Matrix" and the default behaviour when setting the height is to show the part from the top down to [height].
For the animation I'll need the opposite. So if I would set the height to 50dp it would show the bottom 50dp. Then I can move the ImageView down at the same time it's being revealed, thus giving the rolldown curtain effect.
I've looked throught all the different layout and view options and found nothing that seems to do this. So I'm guessing I need to specify the transformation matrix. I looked through the android.graphics.Matrix class but it's a little but too complicated for me. I simply have no idea how to use it.
If there is another, easier, way to do this then that would be fantastic but if not then I really need help with the matrix.
I'm also including the code here:
The Rolldown View XML
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:id="#+id/sliding_accordion"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:src="#drawable/acc_image"
android:contentDescription="#string/accord"
android:scaleType="matrix"
android:layout_below="#+id/acc_button"
android:layout_marginTop="-10dp"
android:layout_centerHorizontal="true"/>
<Button
android:id="#+id/acc_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>
The implementation in code.
(Note, the MyCustomAnimation class is a copy-paste version of the class found here)
//Called from all constructors
private void create()
{
final Context context = getContext();
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
RelativeLayout layout = (RelativeLayout) inflater.inflate(R.layout.widget_accordion, this, false);
final Button theButton = (Button) layout.findViewById(R.id.topic_button);
final ImageView accordionView = (ImageView) layout.findViewById(R.id.sliding_accordion);
accordionView.setVisibility(INVISIBLE);
theButton.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
if (accordionView.getVisibility() == View.VISIBLE)
{
MyCustomAnimation a = new MyCustomAnimation(accordionView, 1000, MyCustomAnimation.COLLAPSE);
height = a.getHeight();
accordionView.startAnimation(a);
}
else
{
MyCustomAnimation a = new MyCustomAnimation(accordionView, 1000, MyCustomAnimation.EXPAND);
a.setHeight(height);
accordionView.startAnimation(a);
}
}
});
this.addView(layout);
}

This took a long time perfect. But I managed to do it after a lot of experimenting.
I animate the margins of the drawer but because of the unexpected behavior of negative margins the button that opens the drawer can not be positioned on top.
When the drawer is closed the XML looks like so:
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/accordion"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<com.animationtest.drawer.Drawer
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/topic_drawer"
android:layout_centerHorizontal="true"
android:layout_marginTop="0dp"
android:visibility="invisible"/>
<com.animationtest.drawer.Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/topic_btn"
android:layout_marginTop="58dp"/>
</RelativeLayout>
Then when the button is pressed the top_margin of the drawer is increased until it has come to whatever position is needed (in this case drawerHeight - someOffset).
I used android.view.animation.Animation to animate the widget my applyTransformation function looks something like this (Note that mLayoutParams are the drawer params):
#Override
protected void applyTransformation(float interpolatedTime, Transformation t) {
int valueDifference = Math.abs(startValue - endValue);
float valueChange = interpolatedTime * valueDifference;
if(currentState.equals(State.COLLAPSED)) {
// is closed and I want to open it
mLayoutParams.topMargin = Math.round(interpolatedTime * valueDifference);
}
else {
// is opened and I want to close it
mLayoutParams.topMargin = valueDifference - Math.round(interpolatedTime * valueDifference);
}
drawerView.requestLayout(); //this is my drawer
}
Finally, to hide the top of the drawer as it moves, I overrode my DrawerView's dispatchDraw method to looks like so:
#Override
protected void dispatchDraw(Canvas canvas) {
float height = getHeight();
float top = height - ((LayoutParams) getLayoutParams()).topMargin;
Path path = new Path();
RectF rectF = new RectF(0.0f, top, getWidth(), height);
path.addRoundRect(rectF, 0.0f, 0.0f, Path.Direction.CW);
canvas.clipPath(path);
super.dispatchDraw(canvas);
}
One final note:
Because of the Button's position one would need to set the widgets margin as a negative number for it to align correctly in a list or layout. In this case it would have to be -58dp.

How does one Animate Layout properties of ViewGroups?

I have the following layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="match_parent"
android:layout_width="match_parent">
<FrameLayout android:id="#+id/viewgroup_left"
android:layout_height="match_parent"
android:layout_weight="2"
android:layout_width="0dp">
... children ...
</FrameLayout>
<LinearLayout android:id="#+id/viewgroup_right"
android:layout_height="match_parent"
android:layout_weight="1"
android:layout_width="0dp"
android:orientation="vertical">
... children ...
</LinearLayout>
</LinearLayout>
I end up with something like this:
+------------------------+------------+
| | |
| | |
| Left | Right |
| | |
| | |
+------------------------+------------+
When a certain toggle is toggled, I want to animate Left so that its width expands to fill the entire screen. At the same time, I would like to animate the width of Right so that it shrinks to zero. Later, when the toggle is toggled again, I need to restore things to the above state.
I've tried writing my own Animation that calls View.getWidth() but when I animate back to that value (by setting View.getLayoutParams().width) it is wider than when it began. I suspect I'm just doing it wrong. I have also read all the documentation on the Honeycomb animation stuff, but I don't want to translate or scale... I want to animate the layout width property. I can't find an example of this.
What is the correct way to do this?

Since noone helped you yet and my first answer was such a mess I'll try to give you the right answer this time ;-)
Actually I like the idea and I think this is a great visual effect which might be useful for a bunch of people. I would implement an overflow of the right view (I think the shrink looks strange since the text is expanding to the bottom).
But anyway, here's the code which works perfectly fine (you can even toggle while it's animating).
Quick explanation:
You call toggle with a boolean for your direction and this will start a handler animation call loop. This will increase or decrease the weights of both views based on the direction and the past time (for a smooth calculation and animation). The animation call loop will invoke itself as long it hasn't reached the start or end position.
The layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:weightSum="10"
android:id="#+id/slide_layout">
<TextView
android:layout_weight="7"
android:padding="10dip"
android:id="#+id/left"
android:layout_width="0dip"
android:layout_height="fill_parent"></TextView>
<TextView
android:layout_weight="3"
android:padding="10dip"
android:id="#+id/right"
android:layout_width="0dip"
android:layout_height="fill_parent"></TextView>
</LinearLayout>
The activity:
public class TestActivity extends Activity {
private static final int ANIMATION_DURATION = 1000;
private View mSlidingLayout;
private View mLeftView;
private View mRightView;
private boolean mAnimating = false;
private boolean mLeftExpand = true;
private float mLeftStartWeight;
private float mLayoutWeightSum;
private Handler mAnimationHandler = new Handler();
private long mAnimationTime;
private Runnable mAnimationStep = new Runnable() {
#Override
public void run() {
long currentTime = System.currentTimeMillis();
float animationStep = (currentTime - mAnimationTime) * 1f / ANIMATION_DURATION;
float weightOffset = animationStep * (mLayoutWeightSum - mLeftStartWeight);
LinearLayout.LayoutParams leftParams = (LinearLayout.LayoutParams)
mLeftView.getLayoutParams();
LinearLayout.LayoutParams rightParams = (LinearLayout.LayoutParams)
mRightView.getLayoutParams();
leftParams.weight += mLeftExpand ? weightOffset : -weightOffset;
rightParams.weight += mLeftExpand ? -weightOffset : weightOffset;
if (leftParams.weight >= mLayoutWeightSum) {
mAnimating = false;
leftParams.weight = mLayoutWeightSum;
rightParams.weight = 0;
} else if (leftParams.weight <= mLeftStartWeight) {
mAnimating = false;
leftParams.weight = mLeftStartWeight;
rightParams.weight = mLayoutWeightSum - mLeftStartWeight;
}
mSlidingLayout.requestLayout();
mAnimationTime = currentTime;
if (mAnimating) {
mAnimationHandler.postDelayed(mAnimationStep, 30);
}
}
};
private void toggleExpand(boolean expand) {
mLeftExpand = expand;
if (!mAnimating) {
mAnimating = true;
mAnimationTime = System.currentTimeMillis();
mAnimationHandler.postDelayed(mAnimationStep, 30);
}
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.slide_test);
mLeftView = findViewById(R.id.left);
mRightView = findViewById(R.id.right);
mSlidingLayout = findViewById(R.id.slide_layout);
mLeftStartWeight = ((LinearLayout.LayoutParams)
mLeftView.getLayoutParams()).weight;
mLayoutWeightSum = ((LinearLayout) mSlidingLayout).getWeightSum();
}
}

Just adding my 2 cents here to Knickedi's excellent answer - just in case someone needs it:
If you animate using weights you will end up with issues with clipping/non-clipping on contained views and viewgroups. This is especially true if you use viewgroups with weight as fragment containers. To overcome it, you might as well need to animate margins of the problematic child views and viewgroups / fragment containers.
And, to do all these things together, its always better to go for ObjectAnimator and AnimatorSet (if you can use them), along with some utility classes like MarginProxy

A different way to the solution posted by #knickedi is to use ObjectAnimator instead of Runnable. The idea is to use ObjectAnimator to adjust the weight of both left and right views. The views, however, need to be customised so that the weight can be exposed as a property for the ObjectAnimator to animate.
So first, define a customised view (using a LinearLayout as an example):
public class CustomLinearLayout extends LinearLayout {
public CustomLinearLayout(Context context) {
super(context);
}
public CustomLinearLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
public CustomLinearLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
public void setMyWeight(float value) {
LinearLayout.LayoutParams p = (LinearLayout.LayoutParams)getLayoutParams();
p.weight = value;
requestLayout();
}
}
Then, update the layout XML to use this custom linear layout.
Then, when you need to toggle the animation, use ObjectAnimator:
ObjectAnimator rightView = ObjectAnimator.ofFloat(viewgroup_right, "MyWeight", 0.5f, 1.0f);
ObjectAnimator leftView = ObjectAnimator.ofFloat(viewgroup_left, "MyWeight", 0.5f, 0.0f);
AnimatorSet animatorSet = new AnimatorSet();
animatorSet.setDuration(1000); // 1 second of animation
animatorSet.playTogether(rightView, leftView);
animatorSet.start();
The above code assumes both views are linear layout and are half in weight to start with. The animation will expand the right view to full weight (so the left one is hidden). Note that ObjectAnimator is animated using the "MyWeight" property of the customised linear layout. The AnimatorSet is used to tie both left and right ObjectAnimators together, so the animation looks smooth.
This approach reduces the need to write runnable code and the weight calculation inside it, but it needs a customised class to be defined.