How to use LinearLayout.LayoutParams to adjust weights in ScrollView (Android Studio) - android

I've been following [this] answer to try to correct the heights of some image buttons in a scroll view, since I can't use linear layout weights. This is the code I've come up with:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_plant_list);
final ImageButton buttonPlant1= (ImageView) findViewById(R.id.buttonPlant1);
final ScrollView scrollViewPlant = (ScrollView) findViewById(R.id.scrollViewPlant);
scrollViewPlant.post(new Runnable() {
#Override
public void run() {
int scrollPlantHeight = scrollViewPlant.getHeight();
LinearLayout.LayoutParams layoutParams = new
LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, scrollPlantHeight / 3.69);
buttonPlant1.setLayoutParams(layoutParams);
}
});
}
I keep getting an alert in my code telling me that I need to import a class before the "LayoutParams.MATCH_PARENT."
When I import a class (I'm not even sure which one to import, but all I've tried is LinearLayout.LayoutParams), I get another alert telling me that it "Cannot resolve constructor 'LayoutParams(int, double)'" at the LayoutParams.MATCH_PARENT.
What class should I import? If any? Or is there something else I'm missing?

LayoutParams Class doesn't have constructor with (int, double).
Try casting the second parameter to integer.
LinearLayout.LayoutParams layoutParams = new
LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, (int)(scrollPlantHeight / 3.69));

Related

Create buttons in sequential order programmatically

I want to parse text, and create for each word - button, but i don't know how to arrange them one after the other
String s = "Alice was beginning to get very tired of sitting";
String[] q = s.split(" ");
for (int i = 0; i < q.length; i++) {
Button myButton = new Button(this);
myButton.setText(q[i]);
RelativeLayout layout = (RelativeLayout) findViewById(R.id.layout1);
layout.addView(myButton, params);
}
See this custom library: FlowLayout
While you're adding views inside FlowLayout, it automatically wraps when there is no space for the next item.
There's not much wrong about your approach, it's only that relative layout as name suggests requires child views to have some parameters to align the views relative to them e.g. above, below etc. As a result you are getting views overlapping each other and hence only the last added view is visible being on top.
Use FlowLayout instead and you'll be fine.
You need to define RelativeLayout parameters as in example below
Heres an example to get you started, fill in the rest as applicable:
TextView tv = new TextView(mContext);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.ALIGN_PARENT_LEFT, RelativeLayout.TRUE);
params.leftMargin = 107
...
mRelativeLayout.addView(tv, params);
The docs for RelativeLayout.LayoutParams and the constructors are
here
From: How to add a view programmattically to RelativeLayout?
Check the link below to get more useful informations.
Hope it will help
In the following code, you should change the upper limits of the for, to a variable.
public class MainActivity
extends Activity
implements View.OnClickListener {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
TableLayout layout = new TableLayout (this);
layout.setLayoutParams( new TableLayout.LayoutParams(4,5) );
layout.setPadding(1,1,1,1);
for (int f=0; f<=13; f++) {
TableRow tr = new TableRow(this);
for (int c=0; c<=9; c++) {
Button b = new Button (this);
b.setText(""+f+c);
b.setTextSize(10.0f);
b.setTextColor(Color.rgb( 100, 200, 200));
b.setOnClickListener(this);
tr.addView(b, 30,30);
} // for
layout.addView(tr);
} // for
super.setContentView(layout);
} // ()
public void onClick(View view) {
((Button) view).setText("*");
((Button) view).setEnabled(false);
}
} // class

How can I set the LayoutParams of an View Programmatically?

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.

Android: Add EditText to View error

bascially I want to have two views. One view is for the canvas, used for drawing rectangles and another view or adding of new editText boxes whenever a rectangle is drawn. When I run my program, an error occured "java.lang.NullPointerException". Is it possible to add the edittext boxes onto the canvas view so that I keep only one view?
My code are as follows:
public class MainActivity extends Activity {
public static DrawRect DR;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
DR = new DrawRect(this);
rectbutton = (Button) findViewById(R.id.rectbutton);
RelativeLayout mainLayout = (RelativeLayout) findViewById(R.id.RelativeLayout);
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT,
RelativeLayout.LayoutParams.MATCH_PARENT);
lp.addRule(RelativeLayout.BELOW, R.id.rectbutton);
DR.setLayoutParams(lp);
mainLayout.addView(DR);
rectbutton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
addRect(); // in my DrawRect class i have this method to draw rect on canvas
addEditText();
}// onclick
});
}
private void addEditText(){
RelativeLayout editTextLayout = new RelativeLayout(this);
EditText editText = new EditText(this);
editTextLayout.addView(editText);
mainLayout.addView(editTextLayout);
}
}
Please Advice. Thank you.
Which line its giving error. if its giving error in
mainLayout.addView(editTextLayout);
means mainLayout is null.you can add EditText in canvas.
the problem is in
RelativeLayout mainLayout = (RelativeLayout) findViewById(R.id.RelativeLayout);
check the id in layout xml.

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);

Activity.addContentView(View) == ViewGroup.addContentView(View)?

I have a question regarding Android Activitys:
An Activity has the Method addContentView(View) while a ViewGroup has a (similar?) addView(View) Method.
Unfortunately its undocumented where the View from addContentView is placed. Is it like a LinearLayout just adding the View to the bottom, or is it more like a FrameLayout, which adds its Views "onTop" ? Does it depend on the ViewGroup set by setContentView?
If I dive into the sources I see that addContentView will call Window's abstract Method addContentView. Unfortunately I cannot see which class is implementing this Method. So whats the behaviour of Activitys addContentView exactly?
The base layout of every activity is a FrameLayout. This means the layout you usually set via setContentView() is a child of this layout. addContentView() adds just another child, therefore it behaves like a FrameLayout (which means it adds new UI elements above existing ones).
You can check this by using a tool called hierachyviewer from your ANDROID_SDK\tools folder. Here are two screenshots:
This is the layout before calling addContentView(), my activity consists of the default FrameLayout, holding a LinearLayout with a Button (my layout here). This is reflected in the bottom row here, the other elements above are the title/statusbar.
After adding a TextView via addContentView() it looks like this. You can see that the base FrameLayout got a new child.
public void addContentView(View view,
LayoutParams params) {
mActivity.addContentView(view, params);
}
//
public static void SetActivityRoot(Activity c) {
View v = ((ViewGroup)c.findViewById(android.R.id.content)).getChildAt(0);
ScrollView sv = new ScrollView(c);
LayoutParams lp = new LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT);
sv.setLayoutParams(lp);
((ViewGroup) v.getParent()).removeAllViews();
sv.addView((View) v);
c.addContentView(sv, lp);
}
//
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
LinearLayout mainLayout =
(LinearLayout)findViewById(R.id.mainlayout);
//newButton added to the existing layout
Button newButton = new Button(this);
newButton.setText("Hello");
mainLayout.addView(newButton);
//anotherLayout and anotherButton added
//using addContentView()
LinearLayout anotherLayout = new LinearLayout(this);
LinearLayout.LayoutParams linearLayoutParams =
new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
Button anotherButton = new Button(this);
anotherButton.setText("I'm another button");
anotherLayout.addView(anotherButton);
addContentView(anotherLayout, linearLayoutParams);
}
}

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