Can't get .getwidth() and .getheight() to work

Can't get .getwidth() and .getheight() to work - java

I know there have been a lot of other questions on this topic, but I've looked through all of them, and still not gotten it to work.
I've made this code for testing:
public class MainActivity extends Activity {
RelativeLayout layout;
TextView widthtext;
TextView heighttext;
int width;
int height;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
layout = (RelativeLayout) findViewById(R.id.rela);
widthtext = (TextView) findViewById(R.id.textView);
heighttext = (TextView) findViewById(R.id.textView2);
layout.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
width = layout.getWidth();
height = layout.getHeight();
}
});
widthtext.setText(width);
heighttext.setText(height);
}
and
<RelativeLayout
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"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context=".MainActivity"
android:id="#+id/rela">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="123"
android:id="#+id/textView"
android:layout_alignTop="#+id/textView2"
android:layout_toLeftOf="#+id/textView2"
android:layout_toStartOf="#+id/textView2"
android:layout_marginRight="50dp"
android:layout_marginEnd="50dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="123"
android:id="#+id/textView2"
android:layout_marginRight="50dp"
android:layout_marginEnd="50dp"
android:layout_centerVertical="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true" />
After a lot of hassle I've now notised that the width and height int's have the right values, though I can't make them display in my TextViews, getting the NullPointerExeption.
Anyone who can make this work?
EXTRA:
public class MainActivity extends Activity {
RelativeLayout layout;
TextView widthtext;
TextView heighttext;
int width;
int height;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
layout = (RelativeLayout) findViewById(R.id.rela);
widthtext = (TextView) findViewById(R.id.textView);
heighttext = (TextView) findViewById(R.id.textView2);
layout.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
width = layout.getWidth();
height = layout.getHeight();
}
});
widthtext.setText(width + "");
heighttext.setText(height + "");
}
}

You are doing this
widthtext.setText(width);
heighttext.setText(height);
outside of your listener so naturally it doesn't have the values yet.
Move them inside
layout.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
width = layout.getWidth();
height = layout.getHeight();
// move here
widthtext.setText(width);
heighttext.setText(height);
}
});
}
As blackbelt pointed out in a comment, you are calling setText() and passing an int. This will look for a resource id of that value. Change those to Strings.
widthtext.setText("" + width);
heighttext.setText("" + height);

setText takes string value
so instead of
setText(width);
setText(height);
do
setText(width+"");
setText(height+"");

Related

Have a problem on creating table Android Studio

I am trying to make a simple app. The program should create a table with given row and column numbers. I'm adding my Java and xml files below:
public class MainActivity extends AppCompatActivity {
private Button btnCreate, btnCalculate, btnReset, btnExit;
private EditText txtColumn, txtRow;
private LinearLayout linLayout, mainLayout;
private TextView txtResult;
private Random random;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnCreate = (Button) findViewById(R.id.btnCreate);
btnCalculate = (Button) findViewById(R.id.btnCalculate);
btnReset = (Button) findViewById(R.id.btnReset);
btnExit = (Button) findViewById(R.id.btnExit);
txtColumn = (EditText) findViewById(R.id.txtColumn);
txtRow = (EditText) findViewById(R.id.txtRow);
txtResult = (TextView) findViewById(R.id.txtResult);
txtColumn.requestFocus();
random = new Random();
LinearLayout mainLayout = findViewById(R.id.mainLayout);
TableLayout table = new TableLayout(this);
btnCalculate.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
}
});
btnCreate.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
table.setLayoutParams(new TableLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
table.setShrinkAllColumns(true);
table.setStretchAllColumns(true);
int columnNumber = Integer.parseInt(txtColumn.getText().toString());
int rowNumber = Integer.parseInt(txtRow.getText().toString());
for (int i=0; i < rowNumber; i++) {
TableRow row = new TableRow(MainActivity.this);
for (int j=0; j < columnNumber; j++) {
int value = random.nextInt(100) + 1;
TextView tv = new TextView(MainActivity.this);
tv.setText(String.valueOf(value));
row.addView(tv);
}
table.addView(row);
}
mainLayout.addView(table);
}
});
btnExit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
System.exit(0);
}
});
btnReset.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
txtColumn.setText(null);
txtRow.setText(null);
txtResult.setText(null);
}
});
}
}
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/linLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<EditText
android:id="#+id/txtRow"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Enter row number"
android:inputType="textCapWords"
android:textSize="18sp" />
<EditText
android:id="#+id/txtColumn"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Enter column number"
android:inputType="textCapWords"
android:textSize="18sp" />
<TextView
android:id="#+id/txtResult"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Result"
android:background="#E91E63"
android:textSize="18sp"
/>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal" >
<Button
android:id="#+id/btnCreate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CREATE"/>
<Button
android:id="#+id/btnCalculate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CALCULATE" />
<Button
android:id="#+id/btnReset"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="RESET" />
<Button
android:id="#+id/btnExit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="EXIT" />
</LinearLayout>
<LinearLayout
android:id="#+id/mainLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
</LinearLayout>
</LinearLayout>
This is the error message that I got:
The specified child already has a parent. You must call removeView() on the child's parent first.
Therefore, whenever I tried to add mainLayout.removeView(table); to the code nothing happens when I click the button create. Thank you all. I will be appreciated for any kinds of comments.

You have the following errors:
1: The layout above the mainLayout layout is letting the height be match_parent. Make mainLayout not displayable.
2: The layout mainLayout is also setting the height to match_parent which is also wrong. I wonder do you understand what match_parent means?
3: The first time you add successfully, but because you are setting the height to match_parent, it makes it not visible, in fact it successfully added the table. The second click because it has been added to the table, it will crash.
The code below I have fixed for you, let's try it.
XML:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/linLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<EditText
android:id="#+id/txtRow"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Enter row number"
android:inputType="textCapWords"
android:textSize="18sp"
android:text="3"/>
<EditText
android:id="#+id/txtColumn"
android:text="2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Enter column number"
android:inputType="textCapWords"
android:textSize="18sp" />
<TextView
android:id="#+id/txtResult"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Result"
android:background="#E91E63"
android:textSize="18sp"
/>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<Button
android:id="#+id/btnCreate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CREATE"/>
<Button
android:id="#+id/btnCalculate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CALCULATE" />
<Button
android:id="#+id/btnReset"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="RESET" />
<Button
android:id="#+id/btnExit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="EXIT" />
</LinearLayout>
<LinearLayout
android:id="#+id/mainLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
</LinearLayout>
</LinearLayout>
JAVA:
public class MainAct extends AppCompatActivity {
private Button btnCreate, btnCalculate, btnReset, btnExit;
private EditText txtColumn, txtRow;
private LinearLayout linLayout, mainLayout;
private TextView txtResult;
private Random random;
TableLayout table;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnCreate = (Button) findViewById(R.id.btnCreate);
btnCalculate = (Button) findViewById(R.id.btnCalculate);
btnReset = (Button) findViewById(R.id.btnReset);
btnExit = (Button) findViewById(R.id.btnExit);
txtColumn = (EditText) findViewById(R.id.txtColumn);
txtRow = (EditText) findViewById(R.id.txtRow);
txtResult = (TextView) findViewById(R.id.txtResult);
txtColumn.requestFocus();
random = new Random();
LinearLayout mainLayout = findViewById(R.id.mainLayout);
btnCalculate.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
}
});
btnCreate.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (table != null) {
mainLayout.removeView(table);
}
table = new TableLayout(getBaseContext());
table.setLayoutParams(new TableLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));
table.setShrinkAllColumns(true);
table.setStretchAllColumns(true);
int columnNumber = Integer.parseInt(txtColumn.getText().toString());
int rowNumber = Integer.parseInt(txtRow.getText().toString());
for (int i=0; i < rowNumber; i++) {
TableRow row = new TableRow(MainAct.this);
for (int j=0; j < columnNumber; j++) {
int value = random.nextInt(100) + 1;
TextView tv = new TextView(MainAct.this);
tv.setText(String.valueOf(value));
row.addView(tv);
}
table.addView(row);
}
if (table != null) {
mainLayout.addView(table);
}
}
});
btnExit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
System.exit(0);
}
});
btnReset.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
txtColumn.setText(null);
txtRow.setText(null);
txtResult.setText(null);
}
});
}
}

Android Buttons same height as width

in my Android App I have 3 Buttons which i set to 33% of the Screen-Width with the weight parameter. Now i want these buttons to have the same height as width, but without "hardcoding" a specific sice to the height, to adjust to different screensizes.
How can i handle this?
Thanks!
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:id="#+id/buttonPlus1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="0.33"
android:layout_margin="5dp"
android:background="#drawable/buttonstyle"
android:text="+1" />
<Button
android:id="#+id/buttonPlus5"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="0.33"
android:layout_margin="5dp"
android:background="#drawable/buttonstyle"
android:text="+5" />
<Button
android:id="#+id/buttonPlus10"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="0.33"
android:layout_margin="5dp"
android:background="#drawable/buttonstyle"
android:text="+10" />
</LinearLayout>

I have come up with a solution and it's tested and working properly.
inside onCreate()
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
b1 = findViewById(R.id.button1);
b2 = findViewById(R.id.button2);
b3 = findViewById(R.id.button3);
layout = findViewById(R.id.linearContainerOfButton);
ViewTreeObserver vto = layout.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
layout.getViewTreeObserver().removeGlobalOnLayoutListener(this);
} else {
layout.getViewTreeObserver().removeOnGlobalLayoutListener(this);
}
int width = b1.getWidth();
ViewGroup.LayoutParams params = b1.getLayoutParams();
Log.d(tag, "width " + width);
params.height = width;
b1.setLayoutParams(params);
b2.setLayoutParams(params);
b3.setLayoutParams(params);
}
});

Expand and collapse Relativelayout by button click

I have this RelativeLayout which expand and collapse on button click
it works fine on one button.
I want to reuse same method on more two RelativeLayout
in same layout
and expand using other two buttons.
This code is running fine. just want more layout to do same action.
Layout:
This is my code:
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="none">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="64dp"
android:background="#FFF"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Title"
android:textSize="20sp" />
<Button
android:id="#+id/viewmore"
android:layout_width="80dp"
android:layout_height="match_parent"
android:layout_marginLeft="280dp"
android:background="#null"
android:text="viewmore" />
</RelativeLayout>
<RelativeLayout
android:visibility="gone"
android:id="#+id/expandable"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:animateLayoutChanges="true"
android:background="#color/colorAccent"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="133dp"
android:text="Text messaging, or texting, is the act of composing and sending electronic messages, typically consisting of alphabetic and numeric characters"
android:textSize="20sp" />
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/textView4"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Title 2"
android:textSize="20sp" />
<Button
android:id="#+id/viewmore1"
android:layout_width="80dp"
android:layout_height="match_parent"
android:layout_marginLeft="280dp"
android:background="#null"
android:text="viewmore" />
</RelativeLayout>
<RelativeLayout
android:visibility="gone"
android:animateLayoutChanges="true"
android:id="#+id/expandable1"
android:layout_width="match_parent"
android:layout_height="100dp"
android:layout_marginTop="30dp"
android:background="#color/colorPrimary">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Text messaging, or texting, is the act of composing and sending electronic messages, typically consisting of alphabetic and numeric characters"
android:textSize="20sp" />
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Title 3"
android:textSize="20sp" />
<Button
android:id="#+id/viewmore2"
android:layout_width="80dp"
android:layout_height="match_parent"
android:layout_marginLeft="280dp"
android:background="#null"
android:text="viewmore" />
</RelativeLayout>
<RelativeLayout
android:visibility="gone"
android:animateLayoutChanges="true"
android:id="#+id/expandable2"
android:layout_width="match_parent"
android:layout_height="100dp"
android:layout_marginTop="30dp"
android:background="#color/colorPrimary">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Text messaging, or texting, is the act of composing and sending electronic messages, typically consisting of alphabetic and numeric characters"
android:textSize="20sp" />
</RelativeLayout>
</LinearLayout>
</ScrollView>
Source Code:
RelativeLayout relativeLayout, relativeLayout1, relativeLayout2;
Button viewmore, viewmore1, viewmore2;
ValueAnimator mAnimator;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.viewmore);
relativeLayout = (RelativeLayout) findViewById(R.id.expandable);
relativeLayout1 = (RelativeLayout) findViewById(R.id.expandable1);
relativeLayout2 = (RelativeLayout) findViewById(R.id.expandable2);
viewmore = (Button) findViewById(R.id.viewmore);
viewmore1 = (Button) findViewById(R.id.viewmore1);
viewmore2 = (Button) findViewById(R.id.viewmore2);
viewmore.setOnClickListener(this);
viewmore1.setOnClickListener(this);
viewmore2.setOnClickListener(this);
relativeLayout.getViewTreeObserver().addOnPreDrawListener(
new ViewTreeObserver.OnPreDrawListener() {
#Override
public boolean onPreDraw() {
relativeLayout.getViewTreeObserver().removeOnPreDrawListener(this);
relativeLayout.setVisibility(View.GONE);
final int widthSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
final int heightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
relativeLayout.measure(widthSpec, heightSpec);
mAnimator = slideAnimator(0, relativeLayout.getMeasuredHeight());
return true;
}
});
}
private void expand() {
relativeLayout.setVisibility(View.VISIBLE);
mAnimator.start();
}
private void collapse() {
int finalHeight = relativeLayout.getHeight();
ValueAnimator mAnimator = slideAnimator(finalHeight, 0);
mAnimator.addListener(new Animator.AnimatorListener() {
#Override
public void onAnimationEnd(Animator animator) {
//Height=0, but it set visibility to GONE
relativeLayout.setVisibility(View.GONE);
}
#Override
public void onAnimationStart(Animator animator) {
}
#Override
public void onAnimationCancel(Animator animator) {
}
#Override
public void onAnimationRepeat(Animator animator) {
}
});
mAnimator.start();
}
private ValueAnimator slideAnimator(int start, int end) {
ValueAnimator animator = ValueAnimator.ofInt(start, end);
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
//Update Height
int value = (Integer) valueAnimator.getAnimatedValue();
ViewGroup.LayoutParams layoutParams = relativeLayout.getLayoutParams();
layoutParams.height = value;
relativeLayout.setLayoutParams(layoutParams);
}
});
return animator;
}
#Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.viewmore:
if (relativeLayout.getVisibility() == View.GONE) {
expand();
} else {
collapse();
}
break;
case R.id.viewmore1:
break;
case R.id.viewmore2:
break;
}
}

To continue with your approach, you will have to make the code apply to all three sections that you have laid out. To do this, you will need to change several of your methods to accept a RelativeLayout as an argument.
First, in your onClick listener, fill in the case blocks so each block calls expand() with the targeted RelativeLayout and maximum height. Call collapse() with the targeted RelativeLayout. You will then need to modify expand() and collapse() to handle the new arguments:
You will notice in the following code that I have changed how and where the animator is created. The animator will need to work with each RelativeLayout.
So, onClick() calls expand() which calls slideAnimator(). For each call, the RelativeLayout that is effected is passed as an argument. In this way, you can generalize the code to work with more than one RelativeLayout.
The pre-draw listener will also need to measure each expandable RelativeLayout.
Here is it all put together:
MainActivity.xml
public class MainActivity extends AppCompatActivity
implements View.OnClickListener {
RelativeLayout relativeLayout, relativeLayout1, relativeLayout2;
Button viewmore, viewmore1, viewmore2;
int height, height1, height2;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.viewmore);
relativeLayout = (RelativeLayout) findViewById(R.id.expandable);
relativeLayout1 = (RelativeLayout) findViewById(R.id.expandable1);
relativeLayout2 = (RelativeLayout) findViewById(R.id.expandable2);
viewmore = (Button) findViewById(R.id.viewmore);
viewmore1 = (Button) findViewById(R.id.viewmore1);
viewmore2 = (Button) findViewById(R.id.viewmore2);
viewmore.setOnClickListener(this);
viewmore1.setOnClickListener(this);
viewmore2.setOnClickListener(this);
relativeLayout.getViewTreeObserver().addOnPreDrawListener(
new ViewTreeObserver.OnPreDrawListener() {
#Override
public boolean onPreDraw() {
relativeLayout.getViewTreeObserver().removeOnPreDrawListener(this);
relativeLayout.setVisibility(View.GONE);
relativeLayout1.setVisibility(View.GONE);
relativeLayout2.setVisibility(View.GONE);
final int widthSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
final int heightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
relativeLayout.measure(widthSpec, heightSpec);
height = relativeLayout.getMeasuredHeight();
relativeLayout1.measure(widthSpec, heightSpec);
height1 = relativeLayout.getMeasuredHeight();
relativeLayout2.measure(widthSpec, heightSpec);
height2 = relativeLayout.getMeasuredHeight();
return true;
}
});
}
private void expand(RelativeLayout layout, int layoutHeight) {
layout.setVisibility(View.VISIBLE);
ValueAnimator animator = slideAnimator(layout, 0, layoutHeight);
animator.start();
}
private void collapse(final RelativeLayout layout) {
int finalHeight = layout.getHeight();
ValueAnimator mAnimator = slideAnimator(layout, finalHeight, 0);
mAnimator.addListener(new Animator.AnimatorListener() {
#Override
public void onAnimationEnd(Animator animator) {
//Height=0, but it set visibility to GONE
layout.setVisibility(View.GONE);
}
#Override
public void onAnimationStart(Animator animator) {
}
#Override
public void onAnimationCancel(Animator animator) {
}
#Override
public void onAnimationRepeat(Animator animator) {
}
});
mAnimator.start();
}
private ValueAnimator slideAnimator(final RelativeLayout layout, int start, int end) {
ValueAnimator animator = ValueAnimator.ofInt(start, end);
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
//Update Height
int value = (Integer) valueAnimator.getAnimatedValue();
ViewGroup.LayoutParams layoutParams = layout.getLayoutParams();
layoutParams.height = value;
layout.setLayoutParams(layoutParams);
}
});
return animator;
}
#Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.viewmore:
if (relativeLayout.getVisibility() == View.GONE) {
expand(relativeLayout, height);
} else {
collapse(relativeLayout);
}
break;
case R.id.viewmore1:
if (relativeLayout1.getVisibility() == View.GONE) {
expand(relativeLayout1, height1);
} else {
collapse(relativeLayout1);
}
break;
case R.id.viewmore2:
if (relativeLayout2.getVisibility() == View.GONE) {
expand(relativeLayout2, height2);
} else {
collapse(relativeLayout2);
}
break;
}
}
}

You can also create own custom expandable which extend android relative layout. On that custom view you can store expanded or collapsed status. As well as you can create custom attributes for define your view default status like expanded or collapsed. So you don't need to compare view status you will just call your toggle function which toggle your view expanded to collapse or vice versa
If you want to show collapsed view as a default view you should not change view visibility before onMeasure function and store your view measured height. If you change visibility on view constructor onMeasure function skip calculation for that view. You should toggle visibility on onPreDraw function.

How to take a variable in my java file and connect it to an XML file

Having trouble with a weatherapp project. The requirements are :
Design the UX for "Now" and 3 days in the future
Design the Java code for the variables (hard code for now)
Connect the java values to the UX so it shows on the page what you have coded in Java. My code looks like :
public class MainActivity extends AppCompatActivity {//start class
int now = 45;
int todayHigh = 56;
int todayLow = 40;
int tomHigh = 70;
int tomLow = 40;
int thurHigh = 45;
int thurLow = 42;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
private void displayNow(int now)
{
TextView quantityTextView = (TextView) findViewById(R.id.now);
quantityTextView.setText(now);
}
and the xml file looks like
<TextView
android:id="#+id/now"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="16dp"
android:textSize="20sp"
android:text="Now: "/>
<TextView
android:id="#+id/today"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="16dp"
android:textSize="20sp"
android:text="Today: "/>
<TextView
android:id="#+id/tomorrow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="16dp"
android:textSize="20sp"
android:text="Tomorrow: "/>
<TextView
android:id="#+id/thursday"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="16dp"
android:textSize="20sp"
android:text="Thursday: "/>
</LinearLayout>
Basically i'm trying to get the variable i have for now (int now =45) to display next to the text view i labeled "now" when i run the app, but nothing is showing. Thanks for the help!

Inside OnCreate() call displayNow
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
displayNow(now);
}

public class MainActivity extends AppCompatActivity {//start class
int now;
int todayHigh;
int todayLow;
int tomHigh;
int tomLow;
int thurHigh;
int thurLow;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
now = 45;
todayHigh = 56;
todayLow = 40;
tomHigh = 70;
tomLow = 40;
thurHigh = 45;
thurLow = 42;
TextView quantityTextView = (TextView) findViewById(R.id.now);
displayNow(int now)
}
private void displayNow(int nowInt)
{
quantityTextView.setText(nowInt);
}}

Unable to Create textView and editText onClick (although method is reached in debugger)

I have a textView and an editText which should be displayed below my imageView (sqwhite) however for some reason - I cannot see either the textView (tx) or the editText (et) (after clicking the button which successfully displays the imageView).
The strange part is I can debug and step through these methods... yet no textView or editText ever seems to appear on the screen (the imageView sqwhite appears without issue though).
Java Snippet:
private boolean isErase = false;
private EditText et;
private TextView tx;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.demo);
et = (EditText) findViewById(R.id.editText1);
et.setVisibility(View.INVISIBLE);
tx = (TextView) findViewById(R.id.textView1);
...
public void addNewImageToScreen() {
int resourceId = R.drawable.sqwhite;
addNewTextToScreen();
int m = mImageCount % 3;
if (m == 1)
resourceId = R.drawable.sqdrk;
else if (m == 2)
resourceId = R.drawable.sqwhite;
addNewImageToScreen(resourceId);
}
private void addNewTextToScreen() {
// TODO Auto-generated method stub
et.setVisibility(View.VISIBLE);
if (isErase) {
tx.setText(et.getText().toString());
} else {
tx.setText("");
et.setVisibility(View.GONE);
}
isErase = !isErase;
}
XML Snippet:
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content" >
<ImageView
android:id="#+id/sqwhite"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="center" />
<EditText
android:id="#+id/editText1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/sqwhite" >
<requestFocus />
</EditText>
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/editText1"
android:text=""
android:textColor="#android:color/white" />
</RelativeLayout>

The first time you go through addNewTextToScreen, isErase is false, so the visibility is set to gone. That's why it doesn't appear

The width and height of your ImageView are set to fill_parent, that is likely pushing your other views offscreen. At the very minimum, height should be changed to something else.

Develop Reference

Java is a programming language and computing platform first released by Sun Microsystems in 1995.

Can't get .getwidth() and .getheight() to work - java

setText takes string value so instead of setText(width); setText(height); do setText(width+""); setText(height+"");

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How to take a variable in my java file and connect it to an XML file

Unable to Create textView and editText onClick (although method is reached in debugger)

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