Develop Reference

Moving buttons at desired locations

I have this problem: I want to put some Buttons at a certain locations, for example at the four squares of the screen (resolved) and I also want them to become red when clicking on each one, at exactly those locations (not resolved yet).
This is the main xml:
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/scrollView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true"
android:layout_weight="15"
android:orientation="vertical">
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:components="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:id="#+id/layout1">
<Button
android:id="#+id/one"
android:layout_width="40dp"
android:layout_height="40dp"
android:background="#color/colorPrimary"/>
<Button
android:id="#+id/two"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_alignParentEnd="true"
android:background="#color/colorPrimary" />
<Button
android:id="#+id/three"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_alignParentBottom="true"
android:background="#color/colorPrimary" />
<Button
android:id="#+id/four"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
android:background="#color/colorPrimary"/>
</RelativeLayout>
</ScrollView>
</android.support.constraint.ConstraintLayout>
And this is the main java:
RelativeLayout layout = (RelativeLayout) findViewById(R.id.layout1);
RelativeLayout.LayoutParams rel_btn = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
Button btnTag = new Button(this);
btnTag.setLayoutParams(rel_btn);
btnTag.setBackgroundColor(Color.BLUE);
btnTag.setOnClickListener(listen);
layout.addView(btnTag);
}
private View.OnClickListener listen = new View.OnClickListener() {
#Override
public void onClick(View view) {
if (pressed != null) {
Button button1 = (Button) pressed;
button1.setBackgroundColor(Color.BLUE);
}
Button button2 = (Button) view;
GradientDrawable drawable = new GradientDrawable();
drawable.setShape(GradientDrawable.RECTANGLE);
drawable.setStroke(8, Color.RED);
button2.setBackgroundDrawable(drawable);
pressed = view;
}

in onCreate set up your buttons:
RelativeLayout layout = (RelativeLayout) findViewById(R.id.layout1);
RelativeLayout.LayoutParams rel_btn = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
Button one = (Button) findViewById(R.id.one);
one.setOnClickListener(listen);
Button two = (Button) findViewById(R.id.two);
two.setOnClickListener(listen);
Button three = (Button) findViewById(R.id.three);
three.setOnClickListener(listen);
Button four = (Button) findViewById(R.id.four);
four.setOnClickListener(listen);
and finally create your listener for all 4 of the buttons:
private View.OnClickListener listen = new View.OnClickListener() {
#Override
public void onClick(View view) {
GradientDrawable drawable = new GradientDrawable();
drawable.setShape(GradientDrawable.RECTANGLE);
drawable.setStroke(8, Color.RED);
Button button = (Button) view;
button.setBackground(drawable);
}
};

If you were created Buttons in the layout then why are you adding it dynamically.
If you are using layout then inflate these buttons using "findViewById()". And when user will click perform the action to that or all buttons.
one.setBackgroundColor(Color.RED);
But if you are using dynamic button creation then store all 4 button id's which you are creating. Then perform something like this.
buttonId[index].setBackgroundColor(Color.RED);

Make your main class implement to View.OnclickListener
public class MainFragment extends Fragment implements View.OnClickListener {
private void setUpViews() {
button1.setOnClickListener(this);
button2.setOnClickListener(this);
button3.setOnClickListener(this);
button4.setOnClickListener(this);
}}
#Override
public void onClick(View view) {
if(view instance of Button){
button.setBackgroundColor(getResources().getColor(android.R.color.holo_red_dark));
}
}
}

Well, if you give those buttons IDs, then you can change the color of them when you click it.
So if you tap on buttonID, do your logic and then change the color to buttonID.
// If you're in an activity:
buttonID.setBackgroundColor(getResources().getColor(R.color.red));
Add the color red to your color xml.
this can go inside of your onCreate. the buttonOne and buttonTwo at the IDs to the buttons in your XML.
This is the most BASIC way to do it. There are more ways, you can see those answers here too.
buttonOne.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//logic here
}
});
buttonTwo.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//logic here
}
});

When you have a listener changing something is relatively easy. You do not need to implement different methods or check every button one by one. Since Button is a View as well, do the following pseudo-code.
// You need this if part, if you have other views that having the same listener.
// Otherwise, you do not need this if check.
if(is Clicked View is Button) {
// Now here, take the clicked view, which we know it is a button and change its colour.
}
By the way, the code above will be inside the overridden method onClick.
EDIT
To clarify, I am adding a small chunk of code.
#Override
public void onClick(View view) {
// Checking if the clicked View is a Button or not.
if(view instanceof Button) {
// view.getId() returns an integer.
Button clickedButton = (Button) findViewById(view.getId());
// Now, change the button's colour.
clickedButton.setBackground(........);
}
}
Hope it helps. Have a nice day!

android How to add button over other button?

I'm trying to add button on other button exactly on same position with same width,and height.
I thought i can do that like these codes,
public class MainActivity extends AppCompatActivity {
Button b1;
LinearLayout root;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
root = (LinearLayout)findViewById(R.id.activity_main);
b1 = (Button)findViewById(R.id.b1);
}
#Override
public void onWindowFocusChanged(boolean hasFocus) {
super.onWindowFocusChanged(hasFocus);
ViewGroup.LayoutParams size = new ViewGroup.LayoutParams(b1.getWidth(),b1.getHeight());
int[] locations = new int[2];
b1.getLocationInWindow(locations);
Button a = new Button(this);
a.setLayoutParams(size);
a.setText("new Button");
a.setX(locations[0]);
a.setY(locations[1]);
root.addView(a);
}
}
and XML
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="5dp"
android:paddingRight="5dp"
android:paddingTop="#dimen/activity_vertical_margin"
android:orientation="vertical"
tools:context="semo.msoft.myapplication.MainActivity">
<Button
android:id="#+id/b1"
android:layout_width="150dp"
android:layout_height="150dp"
android:layout_marginLeft="50dp"
android:layout_marginTop="50dp"/>
</LinearLayout>
but, result was like this,
resultImage
I thought it should be correct but it seems be wrong, new button had little bit smaller width and height. Additionally , the position of new button was totally wrong.. I don't know why,, someone who know about this, please help

The following code is working perfectly fine on my machine. I basically just changed the way you are setting LayoutParams:
int[] locations = new int[2];
b1.getLocationInWindow(locations);
Button a = new Button(this);
a.setLayoutParams(b1.getLayoutParams());
a.setX(locations[0]);
a.setY(locations[1]);
a.setText("new Button");
frameLayout.addView(a);
PS: You need to change the root to <FrameLayout>. LinearLayout just isn't made to handle overlapping views.

Android: Adding buttons at runtime

I'm trying to add some buttons in my TableRow, at runtime. My TableRow has this structure:
<TableRow
android:layout_marginTop="100px"
android:gravity="bottom"
android:paddingTop="50px"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/riga1">
<Button
android:textSize="32px"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="#+id/buttonOK2"
android:text="YES"
android:onClick="setResult"/>
</TableRow>
And my java code is:
TableRow tr = (TableRow) findViewById(R.id.riga1);
Button b = new Button(this);
b.setText("button 1");
b.setId(1);
b.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
tr.addView(b);
Button b1 = new Button(this);
b1.setText("button 2");
b1.setId(2);
b1.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
tr.addView(b1);
But this seems not to work. In my activity I can see only the button defined in the xml file.
Another problem is that if I set in the related TableLayout the parameter:
android:stretchColumns="*"
I must insert (in xml file) at least one button in the TableRow of the aforementioned TableLayout, otherwise I obtain a "division by zero error" near streatchColumns What can I do, in order to let the tableRow empty?

I think that your problem is that you are using the wrong LayoutParams object for your TextViews try this:
TableRow.LayoutParams layoutParams = new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.MATCH_PARENT);
and then set this layoutParams object:
b.setLayoutParams(layoutParams);

Instead of table layout you should use relative layout it's work for me try it
In Your XML File Like this
<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:id="#+id/myMainRelativeLayout"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<Button
android:id="#+id/btnAdd"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="47dp"
android:text="Add Button" />
And your java code like bellow
public class MainActivity extends Activity implements
android.view.View.OnClickListener {
Button btnAdd;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnAdd = (Button) findViewById(R.id.btnAdd);
btnAdd.setOnClickListener(this);
}
#Override
public void onClick(View v) {
if (v.getId() == R.id.btnAdd) {
RelativeLayout rl = (RelativeLayout)findViewById(R.id.myMainRelativeLayout);
Button btn = new Button(this);
btn.setId(1234);
btn.setText("Add Button Runtime");
btn.setOnClickListener(this);
rl.addView(btn);
}
if(v.getId() == 1234)
{
Toast.makeText(getApplicationContext(), "This is Your New Button", Toast.LENGTH_LONG).show();
}
}
}
try this one it's really work

first you need to find the button using this statement
btn=(Button)findViewById(R.id.Button1);
than you can set the visibility using this:
btn.setVisibility(View.INVISIBLE);
Then you can set the Visibility using the statement:
btn.setVisibility(View.VISIBLE);

OnClick of Button more views should be added at runtime in the layout, but I am not able ot do that

I want to add views on click of button. My screen has a text view and an edit text and a "Add More" button. on the click of button another set of text view and edit text should get appended to the screen. I am also planning to add scroll view once the my screen grows longer.
My Code snippet is as follows
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
text.setText("hello how are you?"); //this is just an example, I may want to add lot more here.
linearLayout.addView(text);
setContentView(linearLayout);
}
I know I am missing something very basic but I do not know what is that. :(
Please help.

First of all, you need to initialize each TextView with a reference to the context. So, in your onClick, given that it is in MyActivity.java:
public void onClick(View v) {
TextView text = new TextView(this);
text.setLayoutParams(new LayoutParams(WRAP_CONTENT, WRAP_CONTENT); // Or what you decide
text.setText("Your text");
linearLayout.addView(text);
}
Second, given that you have a call to setContentView in onCreate which also adds your linearlayout to the view, you do not need to call setContentView(linearLayout) each time the button is clicked.

you should first create a new TextView and EditText add it to the linearLayout using linearLayout.addView(). No need to call setContentView() you probably already added it.

This One help you
In your XML file
<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:id="#+id/myMainRelativeLayout"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<Button
android:id="#+id/btnAdd"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="47dp"
android:text="Add Button" />
And your Java file Like
public class MainActivity extends Activity implements
android.view.View.OnClickListener {
Button btnAdd;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnAdd = (Button) findViewById(R.id.btnAdd);
btnAdd.setOnClickListener(this);
}
#Override
public void onClick(View v) {
if (v.getId() == R.id.btnAdd) {
RelativeLayout rl = (RelativeLayout)findViewById(R.id.myMainRelativeLayout);
Button btn = new Button(this);
btn.setId(1234);
btn.setText("Add Button Runtime");
btn.setOnClickListener(this);
rl.addView(btn);
}
if(v.getId() == 1234)
{
Toast.makeText(getApplicationContext(), "This is Your New Button", Toast.LENGTH_LONG).show();
}
}
}
This one just example you can add any view like this

Moving widgets in runtime on Android

I have a simple demo with two buttons. They are laid out with a RelativeLayout at the top and bottom of the screen.
When I click one of them, I want them to switch places.
What is the best way to do that?
This is my res/layout/main.xml :
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ImageButton
android:id="#+id/android_button_1"
android:layout_width="200dip"
android:layout_height="wrap_content"
android:src="#drawable/icon"
android:layout_alignParentTop="true" />
<ImageButton
android:id="#+id/android_button_2"
android:layout_width="200dip"
android:layout_height="wrap_content"
android:src="#drawable/icon2"
android:layout_alignParentBottom="true" />
</RelativeLayout>
And this is my Activity:
public class HelloButtons extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final ImageButton button1 = (ImageButton) findViewById(R.id.android_button_1);
final ImageButton button2 = (ImageButton) findViewById(R.id.android_button_2);
button1.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// Perform action on clicks
Toast.makeText(HelloButtons.this, "Beep Bop", Toast.LENGTH_SHORT).show();
}
});
button2.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// Perform action on clicks
Toast.makeText(HelloButtons.this, "Beep Bop", Toast.LENGTH_SHORT).show();
}
});
}
}

Use something along these lines
RelativeLayout.LayoutParams lp1 = (LayoutParams) b1.getLayoutParams();
RelativeLayout.LayoutParams lp2 = (LayoutParams) b2.getLayoutParams();
lp2.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM, RelativeLayout.TRUE);
lp2.addRule(RelativeLayout.ALIGN_PARENT_TOP, 0);
lp1.addRule(RelativeLayout.ALIGN_PARENT_TOP, RelativeLayout.TRUE);
lp1.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM, 0);
b1.setLayoutParams(lp1);
b2.setLayoutParams(lp2);
(and the opposite to revert them again) in you OnClickListeners

I would say the best way to do that is not to switch the actual ImageButton locations, but to instead switch the ImageButton images and keep track of the state inside your application so it can react to onClicks correctly.