Defining a Linear Layout progmatically - android

I am trying to dynamically create a linear layout with a dynamic number of buttons based on certain parameters. So far I have some code that compiles but when it runs it does not display anything.
public void displayMenu()
{
LinearLayout lin = new LinearLayout(CategoryMenu.this);
lin.setOrientation(LinearLayout.VERTICAL);
lin.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
ArrayList<Button> btnList= new ArrayList<Button>();
//Test Button
Button btn1= new Button(this);
btn1.setText("Dylan");
lin.addView(btn1);
for (int i =0 ; i < 5; i++){
btnList.add(new Button(this));
btnList.get(i).setText("Hello:"+i);
lin.addView(btnList.get(i));
Log.i("CategoryMenu","Adding btn to view");
}
}
What am i doing incorrectly? I'm sure that i'm missing some thing silly here.

you have to add lin to the current hierarchy of view, or creating a new one calling setContentView(lin);

It seems that you're not adding that linear layout to a viewgroup parent.
After all your code you should add something like
myParentViewGroup.add(lin);

Before lin.addView(btn1);
You should define layoutparams for Button like:
// Defining the layout parameters of the Button
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
// Setting the parameters on the Button
tv.setLayoutParams(lp);

You have to add lin too the layout.
At present you have just created a Linearlayout, but you have not attached it to any layout.

LinearLayout lin = new LinearLayout(CategoryMenu.this);
lin.setOrientation(LinearLayout.VERTICAL);
lin.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
ArrayList<Button> btnList= new ArrayList<Button>();

Related

How to make two buttons on the same row in eclipse programmatically?

LinearLayout table = (LinearLayout)findViewById(R.id.linearlayout);
btnControl = new Button(this);
btnControl.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
btnControl.setPadding(0,40,0,40);//x,y,w,h
btnControl.setBackgroundColor(Color.parseColor("#1C344E"));
btnControl.setTextColor(Color.WHITE);
setMargins(btnControl, 50, 50, 50, 50);
btnLogs = new Button(this);
btnLogs.setLayoutParams(new LayoutParams(380, LayoutParams.WRAP_CONTENT));
btnLogs.setPadding(0,40,0,40);//x,y,w,h
btnLogs.setBackgroundColor(Color.parseColor("#1C344E"));
btnLogs.setTextColor(Color.WHITE);
setMargins(btnLogs, 50, 50, 50, 50);
btnLogs.setId(5);
btnLogs.setOnClickListener(this);
btnTermLogs = new Button(this);
btnTermLogs.setLayoutParams(new LayoutParams(380, LayoutParams.WRAP_CONTENT));
btnTermLogs.setPadding(0,40,0,40);//x,y,w,h
btnTermLogs.setBackgroundColor(Color.parseColor("#CC6675"));
btnTermLogs.setTextColor(Color.WHITE);
setMargins(btnLogs, 50, 50, 50, 50);
btnTermLogs.setId(6);
btnTermLogs.setOnClickListener(this);
btnLogout = new Button(this);
btnLogout.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
btnLogout.setPadding(0,40,0,40);//x,y,w,h
btnLogout.setBackgroundColor(Color.parseColor("#CC6675"));
btnLogout.setTextColor(Color.WHITE);
table.addView(btnLogs);
table.addView(btnTermLogs);
I want the two buttons to be aligned together horizontally. However it just align themselves vertically which i dont want.
My buttons look like this:
what i want is to look like this:
Try this below function. It will help
public void addButtons(){
LinearLayout table = (LinearLayout)findViewById(R.id.linearlayout);
LinearLayout linearLayout1 = new LinearLayout(this);
linearLayout1.setOrientation(LinearLayout.VERTICAL);
LinearLayout.LayoutParams LayoutParamsview = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
Button button1 = new Button(this);
button1.setText("Btn 1");
button1.setLayoutParams(LayoutParamsview);
linearLayout1.addView(button1);
table.addView(linearLayout1);
//
LinearLayout linearLayout2 = new LinearLayout(this);
linearLayout2.setOrientation(LinearLayout.HORIZONTAL);
Button button2 = new Button(this);
button2.setText("Btn 2");
button2.setLayoutParams(LayoutParamsview);
Button button3 = new Button(this);
button3.setText("Btn 3");
button3.setLayoutParams(LayoutParamsview);
linearLayout2.addView(button2);
linearLayout2.addView(button3);
table.addView(linearLayout2);
//
LinearLayout linearLayout3 = new LinearLayout(this);
linearLayout3.setOrientation(LinearLayout.VERTICAL);
Button button4 = new Button(this);
button4.setText("Btn 4");
button4.setLayoutParams(LayoutParamsview);
linearLayout3.addView(button4);
table.addView(linearLayout3);
}
Horizontal linear layout supports left to right widgets approach, When
app developer selects horizontal orientation in linear layout then it
will automatically start adding components and widgets to left to
right side after adding them. So here is the complete step by step
tutorial for Creating horizontal linearlayout programmatically
android.
Write this code
//Creating LinearLayout.
LinearLayout Horizontallinearlayout = new LinearLayout(this);
//Setting up LinearLayout Orientation
Horizontallinearlayout.setOrientation(LinearLayout.HORIZONTAL);
LayoutParams Horizontallinearlayoutlayoutparams = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
setContentView(Horizontallinearlayout, Horizontallinearlayoutlayoutparams);
LayoutParams LayoutParamsview = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
//Creating textview .
Button button1 = new Button(this);
Button button2 = new Button(this);
//Adding text to TextView.
button1.setText("First Button");
button2.setText("Second Button");
button1.setLayoutParams(LayoutParamsview);
button2.setLayoutParams(LayoutParamsview);
//Adding textview to linear layout using Add View function.
Horizontallinearlayout.addView(button1);
Horizontallinearlayout.addView(button2);
Hope this helps you
You should use setLayoutParams
Add setOrientation(LinearLayout.HORIZONTAL);
Set the layout parameters associated with this view. These supply
parameters to the parent of this view specifying how it should be
arranged. There are many subclasses of ViewGroup.LayoutParams, and
these correspond to the different subclasses of ViewGroup that are
responsible for arranging their children.
Code Structure
LinearLayout table = (LinearLayout)findViewById(R.id.linearlayout);
table.setOrientation(LinearLayout.HORIZONTAL);
Button Btn1 = new Button(Activity.this);
Btn1.setText("Button 1");
LinearLayout.LayoutParams childParam = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,LinearLayout.LayoutParams.WRAP_CONTENT);
childParam.weight = 0.5f;
Btn1.setLayoutParams(childParam);
Button Btn2 = new Button(Activity.this);
Btn2.setText("Button 2");
LinearLayout.LayoutParams childParam2 = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
childParam2.weight = 0.5f;
Btn2.setLayoutParams(childParam2);
table.addView(Btn1);
table.addView(Btn2);
Respected OP
You can create another XML file, that contains a horizontal LinearLayout, then inflate it and insert the two buttons into it, and then add the whole horizontal LinearLayout to the vertical LinearLayout:
Create an XML file e.g. horizontal_layout.xml:
<LinearLayout
android:id="#+id/horizontal_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
// You will insert the buttons programmatically.
</LinearLayout>
In your Activity use this method to inflate the Layout:
LinearLayout verticalLinearLayout = rootView.findViewById(R.id.vertical_linear_layout);
// Add the first vertical Button regularly.
Button firstVerticalButton = new Button(Activity.this);
firstVerticalButton.setText("Vertical");
verticalLinearLayout.addView(firstVerticalButton);
// Inflate the horizontal LinearLayout and add the two horizontal buttons.
LinearLayout horizontalLinearLayout = getLayoutInflater().inflate(R.layout.horizontal_layout,
linearLayout, false);
Button horizontalOne = new Button(Activity.this);
horizontalOne.setText("Horizontal");
LinearLayout.LayoutParams childParam = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,LinearLayout.LayoutParams.WRAP_CONTENT);
childParam1.weight = 0.5f;
horizontalOne.setLayoutParams(childParam);
Button horizontalTwo = new Button(Activity.this);
horizontalTwo.setText("Horizontal");
LinearLayout.LayoutParams childParam2 = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
childParam1.weight = 0.5f;
horizontalTwo.setLayoutParams(childParam2);
horizontalLinearLayout.addView(horizontalOne);
horizontalLinearLayout.addView(horizontalTwo);
// Insert the inflated layout to the main layout.
verticalLinearLayout.addView(horizontalLinearLayout);
// Add the second vertical Button
Button secondVerticalButton = new Button(Activity.this);
secondVerticalButton.setText("Vertical");
verticalLinearLayout.addView(secondVerticalButton);
use table.setOrientation(LinearLayout.HORIZONTAL); .
Hope it Helps.

method returning Layout or View

The app I am trying to make, has got a lot of similar LinearLayouts and textViews that need to be created programmatically and placed on the screen in a specific order.
So I decided to define a method which returns one element, and for the furthur uses,I will put the method in some loop to produce the others. but when I create a view or layout this way, nothing shows up or sometimes the app crashes, as if it's been sent null to addView(). It only works when I create the View/Layout in onCreate() and then I use it right there afterwards.So , any ideas that I can use the method to creat my Layout/View? Because they are too many and it's not possible to create them one by one in onCreate()
Here's the method:
public LinearLayout createLinearLayout(){
TextView tv_day = new TextView(this);
tv_day.setWidth(LinearLayout.LayoutParams.MATCH_PARENT);
tv_day.setHeight(LinearLayout.LayoutParams.WRAP_CONTENT);
tv_day.setGravity(Gravity.END);
tv_day.setText("27");
LinearLayout ll_horizontal = new LinearLayout(getBaseContext());
LinearLayout.LayoutParams ll_horizontal_params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT);
ll_horizontal.setLayoutParams(ll_horizontal_params);
ll_horizontal.setOrientation(LinearLayout.HORIZONTAL);
ll_horizontal.addView(tv_day);
return ll_horizontal;
}
and this is onCreate() which doesn't add any linear layouts with a textView in it :
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_month_view);
LinearLayout ll= createLinearLayout();
LinearLayout mainLayout = (LinearLayout) findViewById(R.id.activity_month_view);
mainLayout.addView(ll);
}
I think this should help
- add an empty linear layout in XML with some id.
- reference that layout in code
- add elements to that layout dynamically
Hey was just checking your code. Its working perfectly now just try this method.
public LinearLayout createLinearLayout(){
TextView tv_day = new TextView(this);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
tv_day.setLayoutParams(layoutParams);
tv_day.setGravity(Gravity.CENTER);
tv_day.setText("27");
LinearLayout ll_horizontal = new LinearLayout(getBaseContext());
LinearLayout.LayoutParams ll_horizontal_params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT);
ll_horizontal.setLayoutParams(ll_horizontal_params);
ll_horizontal.setOrientation(LinearLayout.HORIZONTAL);
ll_horizontal.addView(tv_day);
return ll_horizontal;
}

Adding Buttons dynamically in RelativeLayout to LinearLayout

When the user inputs a word, he creates a number of Buttons equal to the length of the word. For example: if user inputs "aaaa" he will create 4 Buttons, side by side, in the first row. Then if the user enters "bb" he will create 2 Buttons, side by side, in the second row. And "ccc" he creates 3 Buttons...
Image to demonstrate:
I dynamically create a RelativeLayout, then dynamically add Buttons to that layout. And finally I add the RelativeLayout to my existing LinearLayout. But the problem is, only one Button is added per row. And my program currently looks like this:
Can someone please me fix this problem?
CODE:
final LinearLayout linearLayout = (LinearLayout) findViewById(R.id.ll_bttn_words);
final LinearLayout.LayoutParams llp = new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
button_test.setOnClickListener(
new View.OnClickListener()
{
public void onClick(View view)
{
RelativeLayout relativeLayout = new RelativeLayout(view.getContext());
RelativeLayout.LayoutParams rlp = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT,
RelativeLayout.LayoutParams.WRAP_CONTENT);
int size = enter_txt.getText().toString().length(); //the user input number of buttons
int id = 1;
for (int i=0; i<size; i++)
{
Button myButton = new Button(view.getContext());
myButton.setBackgroundResource(R.drawable.button);
myButton.setId(id);
rlp.addRule(RelativeLayout.RIGHT_OF, myButton.getId());
relativeLayout.addView(myButton, rlp);
id++;
}
linearLayout.addView(relativeLayout, llp);
rlp.addRule(RelativeLayout.RIGHT_OF, myButton.getId());
This line says that myButton should be added to right of myButton, which doesn't make any sense.
simple way to resolve this is to use the following line instead
rlp.addRule(RelativeLayout.RIGHT_OF, myButton.getId()-1);
But this isn't the best way to do this, you should use LinearLayout with horizontal orientation instead.
The structure should be simple
Just need to add your buttons in 3 different linear layout with orientation horizontal.
Like
<Relative layout>{
<LinearLayout global container with vertical orientation >{
<LinearLayout for 'a' type buttons container with horizontal orientation>
<LinearLayout for 'b' type buttons container with horizontal orientation>
<LinearLayout for 'c' type buttons container with horizontal orientation>
}
}
You guys are right. It is much easier using a LinearLayout. For those interested
final LinearLayout linearLayout = (LinearLayout) findViewById(R.id.ll_bttn_words);
final LinearLayout.LayoutParams llp = new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
button_test.setOnClickListener(
new View.OnClickListener()
{
public void onClick(View view)
{
LinearLayout linearLayout2 = new LinearLayout(view.getContext());
linearLayout2.setOrientation(LinearLayout.HORIZONTAL);
LinearLayout.LayoutParams rlp = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
int size = enter_txt.getText().toString().length();
for (int i=0; i<size; i++)
{
Button myButton = new Button(view.getContext());
myButton.setBackgroundResource(R.drawable.button);
linearLayout2.addView(myButton, rlp);
}
linearLayout.addView(linearLayout2, llp);

LinearLayout Horizontal inside LinearLayout Vertical

I am trying to put a linearlayout vertical inside the linear layout programmatically, but it seems that its not working, the buttons doesnt appear, but the text view appear...
Here is my code:
(this is for a dialog..)
LinearLayout titleLayout = new LinearLayout(m_context);
titleLayout.setOrientation(LinearLayout.VERTICAL);
m_titleView = new TextView(m_context);
m_titleView.setText(title);
LinearLayout horizontalLayout = new LinearLayout(m_context);
titleLayout.setOrientation(LinearLayout.HORIZONTAL);
Button backward = new Button(m_context);
backward.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
backward.setText("Backwards");
Button newDirButton = new Button(m_context);
newDirButton.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
newDirButton.setText("New folder");
horizontalLayout.addView(backward);
horizontalLayout.addView(newDirButton);
titleLayout.addView(m_titleView);
titleLayout.addView(horizontalLayout);
Thanks in advance!
Try setting LayoutParams on horizontalLayout.
Anyway, I'd suggest moving to xml world, as this code is not maintainable.
Edit:
Answer found by the author:
titleLayout.setOrientation(LinearLayout.HORIZONTAL);
should be:
horizontalLayout.setOrientation(LinearLayout.HORIZONTAL);

Android: how to center a button programatically created?

I need to create a button programatically and have it centered on the layout, both horizontally and vertically. I am trying with the following code:
LinearLayout ll = (LinearLayout)findViewById(R.id.layoutItem);
Button b = new Button(this);
b.setBackgroundDrawable(getResources().getDrawable(R.drawable.button));
b.setLayoutParams(new LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.WRAP_CONTENT));
b.setGravity(Gravity.CENTER_HORIZONTAL|Gravity.CENTER_VERTICAL);
ll.addView(b);
But it's not working. The button comes out on top all to the left.
Any clues on how to fix this?
I would do something like:
LinearLayout.LayoutParams ll = (LinearLayout.LayoutParams)b.getLayoutParams();
ll.gravity = Gravity.CENTER;
b.setLayoutParams(ll);
see if that works.
Or you can use a RelativeLayout as your parent View and do the following:
this.testButton= (Button) this.findViewById(R.id.testButton);
RelativeLayout.LayoutParams testLP = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
testLP.addRule(RelativeLayout.CENTER_IN_PARENT);
this.testButton.setLayoutParams(testLP);
You can set several rules for the RelativeLayout.

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