Develop Reference

Set Layout width percentage of the total screen width

Is there's way to set Button width 50% of the total screen size (from java code).
I have found a few answers but i would like to change Button size with java code instead of XML.

Try this out..
DisplayMetrics metrics = new DisplayMetrics();
getActivity().getWindowManager().getDefaultDisplay().getMetrics(metrics);
int height = metrics.heightPixels;
ViewGroup.LayoutParams params = yourButton.getLayoutParams();
params.width = metrics.widthPixels;
try {
double ratio = 0.5;
params.height = Double.valueOf(ratio * height).intValue();
yourButton.setLayoutParams(params);
} catch (Exception e) {
e.printStackTrace();
}

Many ways to achieve this, you could try like below:
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
ViewGroup.LayoutParams params= yourBtn.getLayoutParams();
params.width= width * 1/2;
yourBtn.setLayoutParams(params);
yourBtn.requestLayout();

It's so simple just do.
button.getLayoutParams().width = Resources.getSystem().getDisplayMetrics().widthPixels/2;

I hope it Helps
possible with of Guideline constraint
Guideline
Utility class representing a Guideline helper object for
ConstraintLayout. Helper objects are not displayed on device (they are
marked as View.GONE) and are only used for layout purposes. They only
work within a ConstraintLayout.
A Guideline can be either horizontal or vertical:
Vertical Guidelines have a width of zero and the height of their
ConstraintLayout parent Horizontal Guidelines have a height of zero
and the width of their ConstraintLayout parent Positioning a Guideline
is possible in three different ways:
specifying a fixed distance from the left or the top of a layout
(layout_constraintGuide_begin) specifying a fixed distance from the
right or the bottom of a layout (layout_constraintGuide_end)
specifying a percentage of the width or the height of a layout
(layout_constraintGuide_percent) Widgets can then be constrained to
a Guideline, allowing multiple widgets to be positioned easily from
one Guideline, or allowing reactive layout behavior by using percent
positioning.
See the list of attributes in ConstraintLayout.LayoutParams to set a
Guideline in XML, as well as the corresponding
ConstraintSet.setGuidelineBegin(int, int),
ConstraintSet.setGuidelineEnd(int, int) and
ConstraintSet.setGuidelinePercent(int, float) functions in
ConstraintSet.
<android.support.constraint.Guideline
android:id="#+id/guideline3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
app:layout_constraintGuide_percent="0.50" />
**
Example
**
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.constraint.Guideline
android:id="#+id/guideline3"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:orientation="horizontal"
app:layout_constraintGuide_percent="0.50" />
<TextView
android:id="#+id/textView3"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_marginBottom="8dp"
android:layout_marginTop="8dp"
android:text="TextView"
app:layout_constraintBottom_toTopOf="#+id/guideline4"
app:layout_constraintTop_toTopOf="#+id/guideline3"
tools:layout_editor_absoluteX="104dp" />
<android.support.constraint.Guideline
android:id="#+id/guideline4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
app:layout_constraintGuide_percent="0.80" />
</android.support.constraint.ConstraintLayout>
Example with Layout height 50% of screen
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_marginBottom="8dp"
android:layout_marginTop="8dp"
app:layout_constraintBottom_toTopOf="#+id/guideline4"
app:layout_constraintTop_toTopOf="parent">
</RelativeLayout>
<android.support.constraint.Guideline
android:id="#+id/guideline4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
app:layout_constraintGuide_percent="0.50" />
2nd Way
getDefaultDisplay ()
public abstract Display getDefaultDisplay () Returns the Display upon
which this WindowManager instance will create new windows.
Despite the name of this method, the display that is returned is not
necessarily the primary display of the system (see
Display.DEFAULT_DISPLAY). The returned display could instead be a
secondary display that this window manager instance is managing. Think
of it as the display that this WindowManager instance uses by default.
To create windows on a different display, you need to obtain a
WindowManager for that Display. (See the WindowManager class
documentation for more information.)
Display mDisplay = getWindowManager().getDefaultDisplay();
final int width = mDisplay.getWidth();
final int height = mDisplay.getHeight();
// now simple height/2 use it as u want

something like this perhaps? Not sure if it will work exactly as you want it but thats the general idea of it
Configuration configuration = getActivity().getResources().getConfiguration();
int screenWidthDp = configuration.screenWidthDp;
final float scale = context.getResources().getDisplayMetrics().density;
int pixels = (int) (screenWidthDp * scale);
button1.setWidth(pixels*0.5);

Try
LayoutParams params = new LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
params.setMargins(left, top, right, bottom);
yourbutton.setLayoutParams(params);
Resources r = mContext.getResources();
int px = (int) TypedValue.applyDimension(
TypedValue.COMPLEX_UNIT_DIP,
yourdpmeasure,
r.getDisplayMetrics());

How to write XML code for width and heigh in Java

XML code
<ImageView
android:layout_width="match_parent"
android:layout_height="200dp"
android:id="#+id/imageView"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:background="#drawable/pz"
android:layout_marginTop="5dp" />
I wrote it like this in java
ImageView imageView = new ImageView(MainActivity.this);
imageView.setImageResource(R.drawable.pz);
DisplayMetrics displaymetrics = new DisplayMetrics();
MainActivity.this.getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
int width = displaymetrics.widthPixels;
int height = 300;
imageView.setLayoutParams(new ViewGroup.LayoutParams(width, height));
imageView.setId(i + 1);
li.addView(imageView);
But it looks strange , i want to change height to eg. 200 , instead of changing height it change width.Is there any better way to make it i just want width to MATCH_PARENT and height to be 200dp?

if you want to set any layout parameter to wrap_content or match_parent you should set ViewGroup.LayoutParams.MATCH_PARENT orViewGroup.LayoutParams.MATCH_PARENT constants for constructor parameters
and the constructor gets parameters in px so you have to change it to dp you can use this link

Wrong Y coordinate from TextView on Bitmap using Canvas.drawText

Please help me with my problem or at least give me advice.
I have ImageView with overlayed TextView. The user can drag text to any position on the image. After, I want to save the image with text at chosen position.
Layout (TextView add dynamically to root element):
<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:gravity="center_horizontal|center_vertical">
<FrameLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/root"
android:padding="0dp"
android:layout_margin="0dp">
<ImageView
android:id="#+id/image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:adjustViewBounds="true"
android:scaleType="centerInside"/>
</FrameLayout>
</LinearLayout>
All problem in Y coordinate is always wrong. I'm try 2 function to find X and Y coordinates.
First:
public float[] getPosition(ImageView imageView, TextView textView) {
Matrix matrix = new Matrix();
imageView.getImageMatrix().invert(matrix);
float[] coord = {textView.getX(), textView.getY()};
matrix.mapPoints(coord);
return coord;
}
and better one, using this function give you accurate X.
private float[] getCoordinates(ImageView iv, Bitmap bm, float x, float y){
float projectedX = (float) ((double)x * ((double)bm.getWidth()/(double)iv.getWidth()));
float projectedY = (float) ((double)y * ((double)bm.getHeight()/(double)iv.getHeight()));
return new float[]{projectedX, projectedY};
}
Any advice? Y always higher than the desired position when Canvas draw text.
Here is my code to save data for Canvas.drawText:
Bundle bundle = new Bundle();
TextView textView = (TextView)relativeLayout.getChildAt(i);
bundle.putString("text", ((TextView) relativeLayout.getChildAt(i)).getText().toString());
bundle.putFloatArray("coord", getPosition(imageView,textView));
bundle.putFloat("size", size*scale);
new AsyncDraw().execute(bundle);
And after in AsyncTask:
Bundle bundle = bundles[0];
String text = bundle.getString("text");
float[] coord = bundle.getFloatArray("coord");
Canvas canvas = new Canvas(oriented);
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setTextSize(bundle.getFloat("size"));
canvas.drawText(text, coord[0],coord[1],paint);

Try mapping the height values to your device screen metrics using TypedValue.applyDimension method

How to set relativelayout height equal to its width?

I searched a lot to find out how its gonna work and I got nothing.
I found some java code to do it dynamically but didn't work ant of theme and when opening the program, show a force close.
this is my code:
<LinearLayout android:baselineAligned="false"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<RelativeLayout
android:id="#+id/rlv1"
android:layout_width="match_parent"
android:layout_height="150dp"
android:layout_weight="1"
android:background="#drawable/rectengle2" >
</RelativeLayout>
<RelativeLayout
android:id="#+id/rlv2"
android:layout_width="fill_parent"
android:layout_weight="1"
android:background="#drawable/rectengle" >
</RelativeLayout>
</LinearLayout>
as you can see I created a rectangle shape and used it in a relative layout with a lineaer layout as parent and i splitted that linear layout verticali to two part for each relative layout.
now i want to set these relative layout height equal to its width to get a pure square rectangle.
i tried many way but ... can help me any guy please?? thnaks..

The simplest solution, imo, is to subclass RelativeLayout, and override onMeasure, providing to the super the same size for width and height. For instance
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, widthMeasureSpec);
}
as pointed out by #ZakTaccardi, declare it in your layout like
<com.example.subclassrelativelayout
android:layout_width="match_parent"
android:layout_height="wrap_content" />

Finally I myself found out what to do in this situation. so i'm gonna explain how to solve for those who have or will have my problem.
in my xml ui file I set layout_weight=1 for a pair of relative layout that were in a linear layout to be splitted in the screen and actually width of each of them be the half of my screen width. my problem was about height and i tried many java codes to set relative layout height equals to its width.
finally i calculated the screen width in "DP" Term and set every relative layout's height to this. this is the solved code:
Display display = getWindowManager().getDefaultDisplay();
DisplayMetrics outMetrics = new DisplayMetrics ();
display.getMetrics(outMetrics);
float density = getResources().getDisplayMetrics().density;
float dpWidth = outMetrics.widthPixels / density;
RelativeLayout Rl1 = (RelativeLayout) findViewById(R.id.rlv1);
Rl1.getLayoutParams().height = (int) (dpWidth);
RelativeLayout Rl2 = (RelativeLayout) findViewById(R.id.rlv2);
Rl2.getLayoutParams().height = (int) (dpWidth);
so i got a pure square! Enjoy it. Thanks

second imageview not displaying anything

I have a problem displaying two images (software generated) at the same time.
Here is the xml snippet for the layout containing the imageviews.
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#005400"
android:orientation="horizontal">
<RelativeLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="0.5"
android:background="#ff0000"
>
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/output_img1"
android:contentDescription="First image"/>
</RelativeLayout>
<RelativeLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="0.5"
android:background="#ffff00"
>
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/output_img2"
android:contentDescription="Second Image"/>
</RelativeLayout>
</LinearLayout>
Here is the snippet where i create the objects to address the imageviews (in the onCreateView of the Fragment containing the imageviews:
outImage1 = (ImageView)view.findViewById(R.id.output_img1);
outImage1.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
outImage2 = (ImageView)view.findViewById(R.id.output_img2);
outImage2.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
Here is the function that displays the image (scaling it) in the first imageview (this works, and is part of the code for the Fragment containing the imageviews):
public void displayOutImg(Bitmap map){
int bitmapWidth = map.getWidth();
int bitmapHeight = map.getHeight();
int widthParent = outImage1.getWidth();
int heightParent = outImage1.getHeight();
float density = DisplayContext.getResources().getDisplayMetrics().density;
float xScale = ((float) widthParent * density) / bitmapWidth;
float yScale = ((float) heightParent * density) / bitmapHeight;
float minScale = (xScale<yScale)?xScale:yScale;
Matrix matrix = new Matrix();
matrix.postScale(minScale, minScale);
Bitmap scaled = Bitmap.createBitmap(map, 0, 0, bitmapWidth, bitmapHeight, matrix, true);
outImage1.setImageBitmap(scaled);
}
Here is the function to display the image in the second imageview (this seems to do nothing, and is also in the code of the Fragment containing the imageviews):
public void displayOutImg2(Bitmap map){
int bitmapWidth = map.getWidth();
int bitmapHeight = map.getHeight();
int widthParent = outImage2.getWidth();
int heightParent = outImage2.getHeight();
float density = DisplayContext.getResources().getDisplayMetrics().density;
float xScale = ((float) widthParent * density) / bitmapWidth;
float yScale = ((float) heightParent * density) / bitmapHeight;
float minScale = (xScale<yScale)?xScale:yScale;
Matrix matrix = new Matrix();
matrix.postScale(minScale, minScale);
Bitmap scaled = Bitmap.createBitmap(map, 0, 0, bitmapWidth, bitmapHeight, matrix, true);
outImage2.setImageBitmap(scaled);
}
I am trying to display side by side the images resulting from two different processing methods on the same data, but only the first one shows. I thought it might be a problem with the results of the second method, but even if I pass the results of the first one to the displayOutImg2() nothing shows in the second imageview.
I also tried to see if perhaps I was calling the second function from somewhere in my code that could not access the GUI for some reason. So I called it right after the first one (as in, the line below), to no avail. The functions are called from my main activity, like so (images is the Fragment that contains the imageviews):
public void drawFirst(Bitmap result){
images.displayOutImg1(result);
delayedHide(AUTO_HIDE_DELAY_MILLIS);
}
public void drawSecond(Bitmap result){
images.displayOutImg2(result);
delayedHide(AUTO_HIDE_DELAY_MILLIS);
}
My googling failed me so far, and I was not able to find a solution to this issure, which appears to me should be something rather basic. I am sorry if this is something obvious but I have been programming in java for android only for the past couple weeks.
Thanks.

Are you sure that the image actually not behind the other imageview?? To display views over each other you must use FrameLayout for that. Or just use canvas with paint to draw two images over each other.