How can I set the LayoutParams of an View Programmatically? - android

You know this JoystickView from http://code.google.com/p/mobile-anarchy-widgets/wiki/JoystickView ?
Well, I tried to implement it. No Problems with it. I couldn't change It's size because I Added It programmatically. I somehow found out how to change the size, but now It's stuck in the upper left corner and everything I found for three hours got me a NullPointerException on the LayoutParams param I've created or was rejected because It wasn't castable or something to begin with.
public class GameActivity extends Activity implements JoystickMovedListener{
private GraphicsHolder mGraphicsHolder;
private String TAG = "GameActivity";
/*
* creates a new GraphicsHolder and sets it its ContentView
* the GraphicsThread is being included in the GraphicsHolder
*/
#Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
Log.d(TAG, "created");
FrameLayout gameScreen = new FrameLayout(this);
mGraphicsHolder = new GraphicsHolder(this);
JoystickView Joystick = new JoystickView(this);
// I need to set the Gravity HERE
Joystick.setLayoutParams(new RelativeLayout.MarginLayoutParams(500,500));
gameScreen.addView(mGraphicsHolder);
gameScreen.addView(Joystick);
setContentView(gameScreen);
}
}
Now Here's my Question: can you somehow set the Gravity of this View programmatically?

You can try this
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(500,500);
params.addRule(RelativeLayout.CENTER_IN_PARENT, RelativeLayout.TRUE);
Joystick.setLayoutParams(params);

Try to set gravity center to FrameLayout and use ViewGroup.LayoutParams set Joystick LayoutParams :
FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(FrameLayout.LayoutParams.MATCH_PARENT,FrameLayout.LayoutParams.MATCH_PARENT);
params.gravity = Gravity.CENTER;
gameScreen.setLayoutParams(params);
Joystick.setLayoutParams(new ViewGroup.LayoutParams(500,500));

try this.
FrameLayout.LayoutParams params = (FrameLayout.LayoutParams) Joystick.getLayoutParams();
params.gravity = Gravity.TOP;// desired gravity
Joystick.setLayoutParams(params);
dont change ur code just add this after setContentView(gameScreen); hope it works

Well, I found the answer, but it's a completely different approach, since none of the above or those I found elsewhere worked for me.
I did the following changes in the onCreate method:
mGraphicsHolder = new GraphicsHolder(this);
LayoutInflater inflate = (LayoutInflater)
getSystemService(Context.LAYOUT_INFLATER_SERVICE);
setContentView(mGraphicsHolder);
getWindow().addContentView(inflate.inflate(
R.layout.controllayout, null), new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT,
ViewGroup.LayoutParams.FILL_PARENT));
Joystick = (JoystickView) getWindow().findViewById(R.id.joystickView1);
Joystick.setOnJostickMovedListener(this);
Now I got my Joystick on an XML Layout, but It actually works (at least in my case where nothing else worked), and it's quite easy to make changes in things of Layout etc.

Related

How to add a sort of overlay on top of every activitiy

My app is finished and done. Now the client wants to have a demo functionality. So when running in Demo mode there must be on every screen the tekst "DEMO" in the left corner.
How can I do this by changing minimum of code?
I see solutions with relative layouts and stuff but then I need to change every activity layout?
Thanks to pskink I've found the solution.
In my baseActivity I override my setContentView like this:
#Override
public void setContentView(int layoutResID) {
super.setContentView(layoutResID);
if(config.isInDemoMode()) {
RelativeLayout lContainerLayout = new RelativeLayout(this);
lContainerLayout.setLayoutParams(new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
TextView mCustomView = new TextView(this);
mCustomView.setText("DEMO");
RelativeLayout.LayoutParams lTextViewParams = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
lTextViewParams.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
mCustomView.setLayoutParams(lTextViewParams);
lContainerLayout.addView(mCustomView);
addContentView(lContainerLayout, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
}
}

Adding Views to LinearLayout with weight programmatically

I am getting stucked on the following problem:
For a questions app I want to implement a nice output for a survey showing the possible answers and the percentage of people answered the specific question. Therefore, I want to add a "bar" to my app that displays the percentage. I try to solve this by using views and weighting them in a linear layout.
I want to add the different answers programmatically, this is the code I've got so far.
My problems are, that I am not getting closer to weighting the views and resizing them.
/* Add all questions */
RelativeLayout my_root = (RelativeLayout) findViewById(R.id.ownerRL);
/* Add a new Linearlayout as a container for the question */
LinearLayout A = new LinearLayout(this);
A.setOrientation(LinearLayout.HORIZONTAL);
my_root.addView(A);
/* Create a new View in this container, for the status bar */
View new_view = new View(getBaseContext());
new_view.setBackgroundColor(Color.YELLOW);
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(50, 20, 3);
RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) A.getLayoutParams();
params.addRule(RelativeLayout.BELOW, R.id.question1);
A.addView(new_view);
View new_view2 = new View(getBaseContext());
new_view.setBackgroundColor(Color.GREEN);
ViewGroup.LayoutParams lp2 = new ViewGroup.LayoutParams(50, 20);
RelativeLayout.LayoutParams params2 = (RelativeLayout.LayoutParams) A.getLayoutParams();
params2.addRule(RelativeLayout.BELOW, R.id.question1);
params2.addRule(RelativeLayout.LEFT_OF, new_view.getId());
A.addView(new_view2);
The Green view should actually be right of the yellow one (which is not visible).
How do get it managed such that it creates a red/white bar that has a height of 4px and the red and weight parts are weighted?
Thanks for your help!
check this link, Set Linear Layout weight it like this
LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT, 1.0f);
The last parameter is weight.Hope this help.

Having trouble positioning android dynamically loaded buttons

I'm creating buttons dynamically in my class, I try to position them using 'offsetLeftAndRight()' or '.leftMargin' and '.topMargin' as follows,
public class instruction extends Activity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.instruct);
final Button btn = new Button(this);
RelativeLayout.LayoutParams paramsd2 =
new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
paramsd2.leftMargin = 500;
paramsd2.topMargin = 500;
paramsd2.height = 60;
paramsd2.width = 200;
btn.offsetLeftAndRight(300);
btn.setLayoutParams(paramsd2);
addContentView(btn, paramsd2);
}
But the button always stays in the top left corner, how can I position it, what am I doing wrong?
AddContentView() is not the proper way to add a view in an already set layout.
make your main layout a RelativeLayout (check this in the instruct.xml layout file)
use its id to retreive a reference on it in your onCreate() method using
myRelativeLayout = (RelativeLayout) this.findViewById(R.id.itsId)
then add your button to this layout :
myRelativeLayout.addView(myButton);
the layout params of your button seems fine for positioning so it should work.
Set margin on button rather then layout
MarginLayoutParams marginParams = new MarginLayoutParams(backToMainScreenImageView.getLayoutParams());
marginParams.setMargins(0, 0, (int) UIUtil.getRadialButtonMainMargin(this), 0);
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(marginParams);
layoutParams.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
backToMainScreenImageView.setLayoutParams(layoutParams);
Try something like this :
paramsd2.setMargin(500, 500, 0, 0);
btn.setLayoutParams(paramsd2);

How to set layout_gravity programmatically?

My question is simple,
How to set my buttons layout_gravity programmatically?
I found this on internet, but it simply throws me a Nullpointer exception:
Button MyButton = new Button(this);
LinearLayout.LayoutParams lllp=(LinearLayout.LayoutParams)MyButton.getLayoutParams();
lllp.gravity=Gravity.RIGHT;
MyButton.setLayoutParams(lllp);
MyLinearLayout.addView(MyButton);
Any solution?
Java
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);
params.weight = 1.0f;
params.gravity = Gravity.TOP;
button.setLayoutParams(params);
Kotlin
val params = LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT
).apply {
weight = 1.0f
gravity = Gravity.TOP
}
For gravity values and how to set gravity check Gravity.
Basically, you should choose the LayoutParams depending on the parent. It can be RelativeLayout, LinearLayout etc...
I'd hate to be resurrecting old threads but this is a problem that is not answered correctly and moreover I've ran into this problem myself.
Here's the long bit, if you're only interested in the answer please scroll all the way down to the code:
android:gravity and android:layout_gravity works differently. Here's an article I've read that helped me.
GIST of article: gravity affects view after height/width is assigned. So gravity centre will not affect a view that is done FILL_PARENT (think of it as auto margin). layout_gravity centre WILL affect view that is FILL_PARENT (think of it as auto pad).
Basically, android:layout_gravity CANNOT be access programmatically, only android:gravity.
In the OP's case and my case, the accepted answer does not place the button vertically centre.
To improve on Karthi's answer:
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
params.gravity = Gravity.CENTER;
button.setLayoutParams(params);
Link to LinearLayout.LayoutParams.
android:layout_gravity shows "No related methods" meaning cannot be access programatically.
Whereas gravity is a field in the class.
I had a similar problem with programmatically setting layout_gravity on buttons in a GridLayout.
The trick was to set gravity on the button layoutParams AFTER the button was added to a parent (GridLayout), otherwise the gravity would be ignored.
grid.addView(button)
((GridLayout.LayoutParams)button.getLayoutParams()).setGravity(int)
MyButton.setGravity(Gravity.RIGHT);
For layout_gravity use the answer stated by "karthi". This method sets gravity to place the children inside the view.
layoutParams2.gravity = Gravity.RIGHT|Gravity.BOTTOM;
use this to add mor than one gravity
If you want to change the layou_gravity of an existing view do this:
((FrameLayout.LayoutParams) view.getLayoutParams()).gravity = Gravity.BOTTOM;
Remember to use the right LayoutParams based on the Layout type your view is in. Ex:
LinearLayout.LayoutParams
KOTLIN setting more than one gravity on FrameLayout without changing size:
// assign more than one gravity,Using the operator "or"
var gravity = Gravity.RIGHT or Gravity.CENTER_VERTICAL
// update gravity
(pagerContainer.layoutParams as FrameLayout.LayoutParams).gravity = gravity
// refresh layout
pagerContainer.requestLayout()
This question is old but I just had the same problem and solved it like this
LayoutParams lay = new LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT)
lay.gravity = Gravity.CENTER;
I use someting like that: (Xamarin and C# code)
LinearLayout linLayout= new LinearLayout(this);
linLayout.SetGravity(GravityFlags.Center);
TextView txtView= new TextView(this);
linLayout.AddView(txtView);
the SetGravity puts my textView in the center of the layout.
So SetGravity layout property refer to layout content
In case you need to set Gravity for a View use the following
Button b=new Button(Context);
b.setGravity(Gravity.CENTER);
For setting layout_gravity for the Button
use gravity field for the layoutparams as
LayoutParams lp=new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
lp.gravity=Gravity.CENTER;
try this
hope this clears
thanks
If you want to put a view in the center of parent, you can do with following code..
public class myLayout extends LinearLayout {
public myLayout(Context context) {
super(context);
RelativeLayout vi = (RelativeLayout) ((LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(
R.layout.activity_main, null);
LinearLayout.LayoutParams cc = new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
cc.gravity = Gravity.CENTER;
this.setGravity(Gravity.CENTER);
this.addView(vi);
}
}
these code section make LinearLayout put the first view elements in the center of parent.
So, we system don't consider the initial width and high to arrange view in the center .
I do the code section well.
The rest of the answers are right, I want to add more explaination. The layout_gravity is about how to position the view in parent view.
You must set gravity **after method parentView.addView() ** was called. We can see the code:
public void setLayoutParams(ViewGroup.LayoutParams params) {
if (params == null) {
throw new NullPointerException("Layout parameters cannot be null");
}
mLayoutParams = params;
resolveLayoutParams();
if (mParent instanceof ViewGroup) {
((ViewGroup) mParent).onSetLayoutParams(this, params);
}
requestLayout();
}
And the problem of null pointer is because it's not calling addView before getLayoutParams().
The annotation was already said "This method may return null if this View is not attached to a parent ViewGroup or {#link#setLayoutParams(android.view.ViewGroup.LayoutParams)} was not invoked successfully. When a View is attached to a parent ViewGroup, this method must not return null."
to RelativeLayout, try this code , it works for me:
yourLayoutParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
Perfectly Working!!! None of the above answer works for me. In Xml file setting gravity and setting layout_gravity is different. Check out the below code
// here messageLL is the linear layout in the xml file
// Before adding any view just remove all views
messageLL.removeAllViews();
// FrameLayout is the parent for LinearLayout
FrameLayout.LayoutParams params = new
FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
params.gravity = Gravity.CENTER|Gravity.CENTER_VERTICAL;
messageLL.setLayoutParams(params);
messageText.setVisibility(View.GONE);
messageNoText.setVisibility(View.VISIBLE);
messageLL.addView(messageNoText);
Also check This,where you can find clear explanation about gravity and layout_gravity .
Most of above answer are right, so written a helper methods, so you can use it
directly in you project .
set layout_gravity programmtically
// gravity types : Gravity.BOTTOM, Gravity.START etc.
// view : can be any view example : button, textview, linearlayout, image etc.
// for single view
public static void setLayoutGravity(int gravity, View view){
((LinearLayout.LayoutParams) view.getLayoutParams()).gravity = gravity;
}
// for mulitple views
public static void setLayoutGravity(int gravity, View ...view){
for(View item : view)
((LinearLayout.LayoutParams) item.getLayoutParams()).gravity = gravity;
}
Modify the existing layout params and set layout params again
//Get the current layout params and update the Gravity
(iv.layoutParams as FrameLayout.LayoutParams).gravity = Gravity.START
//Set layout params again (this updates the view)
iv.layoutParams = layoutParams
I switched from LinearLayout.LayoutParams to RelativeLayout.LayoutParams to finally get the result I was desiring on a custom circleview I created.
But instead of gravity you use addRule
RelativeLayout.LayoutParams mCircleParams = new RelativeLayout.LayoutParams(circleheight,circleheight);
mCircleParams.addRule(RelativeLayout.CENTER_IN_PARENT);
int width=getResources().getDisplayMetrics().widthPixels;
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams
(width, width);
params.gravity = Gravity.CENTER;
iv_main_text = new HTextView(getContext());
iv_main_text.setLayoutParams(params);
iv_main_text.setBackgroundColor(Color.BLUE);
iv_main_text.setTextSize(60);
iv_main_text.setGravity(Gravity.CENTER);
iv_main_text.setTextColor(Color.BLACK);
FloatingActionButton sendFab = new FloatingActionButton(this);
FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
layoutParams.setMargins(32, 32, 32, 32);
layoutParams.gravity = Gravity.END|Gravity.BOTTOM;
sendFab.setLayoutParams(layoutParams);
sendFab.setImageResource(android.R.drawable.ic_menu_send);
Try this code
Button btn = new Button(YourActivity.this);
btn.setGravity(Gravity.CENTER | Gravity.TOP);
btn.setText("some text");
or
btn.setGravity(Gravity.TOP);

How to align a dynamically create UserInterface using RelativeLayout in Android

I want to create a relative Layout dynamically through code with 2 Textviews one below the other.How to implement android:layout_below property through code in Android.
can anyone help me in sorting out this issue.
Thanks in Advance,
final TextView upperTxt = (...)
upperTxt.setId(12345);
final TextView lowerTxt = (...);
final RelativeLayout.LayoutParams params = RelativeLayout.LayoutParams(this, null);
params.addRule(RelativeLayout.BELOW, 12345);
lowerTxt.setLayoutParams(params);
Here is my solution for my special Problem.
In case the username wouldn't be found in the db i had to create a RelativeLayout that looks like the xml-generated one.
// text view appears on top of the edit text
enterNameRequest = new TextView(mainActivity.getApplicationContext());
// fill the view with a string from strings.xml
enterNameRequest.setText(mainActivity.getResources().getString(R.string.enterNameRequest));
// edit text appears below text view and above button
enterName = new EditText(mainActivity.getApplicationContext());
enterName.setId(667);
// button appears at the bottom of the relative layout
saveUserName = new Button(mainActivity.getApplicationContext());
saveUserName.setText(mainActivity.getResources().getString(R.string.useUserName));
saveUserName.setId(666);
// generate the relative layout
RelativeLayout layout = new RelativeLayout(mainActivity.getApplicationContext());
layout.setId(668);
// set a background graphic by its id
layout.setBackgroundDrawable(mainActivity.getApplicationContext().getResources().getDrawable(R.drawable.background_head_neutral));
// runtime told me that i MUST use width and height parameters!
LayoutParams params2 = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
params2.addRule(RelativeLayout.ABOVE, 666);
enterName.setLayoutParams(params2);
LayoutParams params3 = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
params3.addRule(RelativeLayout.ABOVE, 667);
enterNameRequest.setLayoutParams(params3);
LayoutParams params4 = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
params4.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM, 668);
saveUserName.setLayoutParams(params4);
// add views
layout.addView(enterNameRequest);
layout.addView(enterName);
layout.addView(saveUserName);
/* todo: set button action */
mainActivity.setContentView(layout);
What i found out additionally:
It is not so good to manipulate the layout manually from within java!
You should better use a new Activity and set a new layout in it.
This way, the application-code is readable a lot better!
I even tried to set several layouts (not manually, but wit setContentView) in one activity, and it turned out that i didn't know where what was accessing what else... Also, i had a great problem in adding onClickListeners... so you better use -- android:onClick="myButtonMethod" -- in your button tag in the xml and have a method in your according activity, which uses the layout, like this:
public void myButtonMethod(View v){
// do stuff
}
This improves performance because you are not using additional Listeners - but you use the already available Listener that is bound to your activity in every case.
u can try this
LinearLayout.LayoutParams leftMarginParams = new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);``
leftMarginParams.leftMargin = 50;
Button btn1 = new Button(this);
btn1.setText("Button1");
linLayout.addView(btn1, leftMarginParams)

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