ImageView manipulation in Java - android

I have an ImageView created in my xml layout. I then access the ImageView in my Java with the following:
ImageView iv1 = (ImageView) findViewById(R.id.iv1);
I'm then accessing the ImageView's OnClick method. When the ImageView is clicked I would like to change it's position on the screen. In the XML side I can do this with layout_margin, but I can't figure out how that is done in the Java side.
Could anyone point me in the right direction? Thanks in advance!

You can set margins programmatically using LayoutParams, please try with following code:
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
layoutParams.setMargins(30, 20, 30, 0);
and set this layout param object to your view by using:
view.setLayoutParams(layoutParams);

i think you should change layout parameters by setLayoutParamerter method of View class see Discription.
this is not the big task, even you can add this view at any particular place by using Relative layout.

Related

android textview set height does not work

I am trying to create a layout with nested linear layouts and textviews which are placed vertically in a linear layout. They are created programatically. While I can set the height of the linear layout using layout Params I am not able to do this for textview. Using Textview setLayoutParams or setHeight function provides no response. The text is always wrapped around the content (though this is no where mentioned by me in the code). Can someone help me fix this?
this code might help you:
LinearLayout.LayoutParams paramsLayoutExpire = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);
TextView txtView=new TextView(this);
txtView.setLayoutParams(paramsTextViewExpire);
LayoutParams.MATCH_PARENT: Height
LayoutParams.WRAP_CONTENT: Width
I hope this might help
TextView textView = new TextView(this);
textView.setText("Hellow World");
textView.setHeight(prefered_height_in_pixel);
this.addView(textView)

Android Set ImageView in front of Relative Layout

I have a RelativeLayout in my Android App. Now I want to show an ImageView in front of that Layout. The problem is that the ImageView is not in the front, it's a bit transparent and I can see things like EditText and Button. I can't change the Layout (setContentView), because the Layout is created dynamically and after setContentView, the Controls are away.
You can add view programmatically, and in the way that it will be on the top!
create id for you top level layout
Now some code (in my case it's relative layout):
RelativeLayout relativeLayout = (RelativeLayout)findViewById(R.id.relative_layout_id);
ImageView imageView = new ImageView(context)
Drawable rightArrowBlackDrawable = getResources().getDrawable(R.drawable.image);
imageView.setLayoutParams(getLayoutParams());
relativeLayout.addView(imageView);
imageView.bringToFront();
//here just example layout params, use yours params ;-)
private RelativeLayout.LayoutParams getLayoutParams() {
RelativeLayout.LayoutParams layoutParams =
new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,
RelativeLayout.LayoutParams.WRAP_CONTENT);
layoutParams.addRule(RelativeLayout.CENTER_VERTICAL);
return layoutParams;
}
You can bring it to the front once you insert it.
imageView.bringToFront();
If the image is transparent, you can set a white background to prevent things below it from showing.
imageView.setBackgroundColor(0xFFFFFF);

How to overlap views in RelativeLayout, dynamically?

I've an ImageView inserted in the RelativeLayout. On top of this ImageView I'm trying to insert a progressbar, which would go invisible after the image is downloaded. But, when I add progressbar after adding the ImageView, it gives me an error -
java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
Here is the code:
mRelativeLayout = (RelativeLayout) mGallery.findViewById(R.id.relative_progress_spin_layout);
RelativeLayout.LayoutParams relativeLayoutParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
relativeLayoutParams.addRule(RelativeLayout.ALIGN_TOP, R.id.progress_spin);
progressBar = (ProgressBar) mGallery.findViewById(R.id.progress_spin);
image = new ImageView(GalleryModuleActivity.this);
image.setPadding(4, 4, 4, 4);
image.setScaleType(ImageView.ScaleType.FIT_XY);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(200, LinearLayout.LayoutParams.MATCH_PARENT);
image.setLayoutParams(layoutParams);
mRelativeLayout.addView(image);
mRelativeLayout.addView(progressBar);
mHorizontalLayout.addView(mRelativeLayout);
Thanks..
You already have the ProgressBar in the layout(you search for it with findViewById) so you shouldn't add it again to the layout(the same thing with the mRelativeLayout RelativeLayout if it is already in the layout file). Remove this lines:
mRelativeLayout.addView(progressBar);
mHorizontalLayout.addView(mRelativeLayout);
If you have the views in the layout you don't add them again to the layout!
What you exactly want to do with images and progress bar. If you want to display ProgressBar on images use FrameLayout. In that also you can use VISIBLE and GONE stuff.
Where you want to display that dynamic generated views ?
Because we do have adapter to display same type of data with different content.

Android FrameLayout and TextView - why does LayoutParams work where setGravity() does not?

I'm using a FrameLayout to display (on demand) some text on the screen. I want the text to be in a certain place, so I thought setGravity() would do the job... but no, it seems to have no effect whatsoever on where the text goes (and other objects like ImageView don't even have this method).
So first, what exactly is TextView.setGravity() used for? (Edit: I understand this much better now, thanks! Still not clear on the following part of the question though.)
Second, it seems the only way to update a FrameLayout in this way is to create a new FrameLayout.LayoutParams object with the settings you want, and then use the setLayoutParams() method to apply it. (This seems to automatically update the view so is a requestLayout() call necessary?) And is there a simpler / more straightforward way to achieve this for a FrameLayout... say, without creating a new LayoutParams object as I'm doing now?
Thanks! For reference, below is a (working) code snippet showing how I'm setting up this FrameLayout and TextView.
FrameLayout fl1 = new FrameLayout(this);
FrameLayout.LayoutParams flp1 = new FrameLayout.LayoutParams(
LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
fl1.setId(9001);
fl1.setLayoutParams(flp1);
.....
tv1 = new TextView(this);
FrameLayout.LayoutParams tvp1 = new FrameLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT,
(Gravity.CENTER_HORIZONTAL | Gravity.BOTTOM));
tv1.setId(9006);
tv1.setLayoutParams(tvp1); // This works
tv1.setBackgroundColor(Color.GRAY);
tv1.setTextColor(Color.BLACK);
tv1.setText("Dynamic layouts ftw!");
tv1.setGravity(Gravity.CENTER); // This does NOT work
.....
fl1.addView(tv1);
1) view.setGravity means hows the view should positions if children.
In the case of the textview it refers to the positioning of the text.
When in linearlayouts or viewgroups it refers to its child views.
2) I checked your code. You are already using textview.setGravity method. In that case you dont need to specify gravity parameters in the FrameLayout.LayoutParams constructor.
Other thing I noticed is that you gave the textview the width and height as wrap content which will only take the size of the text. So there is no meaning in giving gravity as the textview has no extra area to position the text to the center. You need to give the width of the textview as fill_parent. That should make your gravity property work.
Btw this is a very good article about Gravities. It explains both about gravity and the layout_gravity attribute.
If you want your textview to wrap the content then you should add your textview to a linearlayout and setgravity to the linear layout.
This should give what your are trying to do
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT);
FrameLayout fr = new FrameLayout(this);
fr.setLayoutParams(lp);
fr.setBackgroundColor(Color.RED);
LinearLayout.LayoutParams lp2 = new LinearLayout.LayoutParams(
LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT);
LinearLayout l = new LinearLayout(this);
l.setLayoutParams(lp2);
l.setGravity(Gravity.CENTER);
l.setBackgroundColor(Color.BLUE);
ViewGroup.LayoutParams vp = new ViewGroup.LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
TextView t = new TextView(this);
t.setLayoutParams(vp);
t.setText("Blessan Mathew");
t.setBackgroundColor(Color.CYAN);
l.addView(t);
fr.addView(l);
tv1.setGravity(Gravity.CENTER);
belongs to the gravity of the TEXT inside the TextView.
As documentation states:
Sets the horizontal alignment of the text and the vertical gravity
that will be used when there is extra space in the TextView beyond
what is required for the text itself.

How to Change Margin of TextView

I have TextView added Programmatically in to LinearLayout and on some external events I want to decrease bottom margin of that TextView to -10, for that I tried following.
LinearLayout.LayoutParams lastTxtParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
lastTxtParams.setMargins(0, 0, 0, -10);
mOldTextView.setLayoutParams(lastTxtParams);
mOldTextView.invalidate();
Is the right way of modifying Margin of widget that has been added to View?
Some how it is not working.
TextView forgot_pswrd = (TextView) findViewById(R.id.ForgotPasswordText);
forgot_pswrd.setOnTouchListener(this);
LinearLayout.LayoutParams llp = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
llp.setMargins(50, 0, 0, 0); // llp.setMargins(left, top, right, bottom);
forgot_pswrd.setLayoutParams(llp);
I did this and it worked perfectly.
Maybe as you are giving the value in -ve, that's why your code is not working.
You just put this code where you are creating the reference of the view.
Your layout in xml probably already has a layout_margin(Left|Right|etc) attribute in it, which means you need to access the object generated by that xml and modify it.
I found this solution to be very simple:
ViewGroup.MarginLayoutParams mlp = (ViewGroup.MarginLayoutParams) mTextView
.getLayoutParams();
mlp.setMargins(adjustmentPxs, 0, 0, 0);
break;
Get the LayoutParams instance of your textview, downcast it to MarginLayoutParams, and use the setMargins method to set the margins.
This one is tricky problem, i set margin to textview in a row of a table layout.
see the below:
TableLayout tl = new TableLayout(this);
tl.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
TableRow tr = new TableRow(this);
tr.setBackgroundResource(R.color.rowColor);
LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
params.setMargins(4, 4, 4, 4);
TextView tv = new TextView(this);
tv.setBackgroundResource(R.color.textviewColor);
tv.setText("hello");
tr.addView(tv, params);
TextView tv2 = new TextView(this);
tv2.setBackgroundResource(R.color.textviewColor);
tv2.setText("hi");
tr.addView(tv2, params);
tl.addView(tr);
setContentView(tl);
the class needed to import for LayoutParams for use in a table row is :
import android.widget.**TableRow**.LayoutParams;
important to note that i added the class for table row. similarly many other classes are available to use LayoutParams like:
import android.widget.**RelativeLayout**.LayoutParams;
import android.widget.LinearLayout.LayoutParams;
so use accordingly.
setMargins() sets the INNER margins of the TextView, not the layout-margins. Is that what you want to do? This two different margins can be quite complicated.
If you want to set the layout margins, change the LayoutParams of the TextView (textview.getLayoutParams(), then change the parameters on the returned LayoutParams object).
You don't need to change anything on your LinearLayout.
Regards,
Oliver
TextView does not support setMargins. Android docs say:
Even though a view can define a padding, it does not provide any support for margins. However, view groups provide such a support. Refer to ViewGroup and ViewGroup.MarginLayoutParams for further information.
Here is another approach...
When I've got to the same problem, I didn't like the suggested solutions here.
So, I've come up with another way:
I've inserted a TextView in the XML file between the two fields I wanted to separate with two important fields:
visibility set to "GONE" (doesn't occupy any space..)
height is set to whatever I needed the separation to be.
XML:
...//some view up here
<TextView
android:id="#+id/dialogSeparator"
android:layout_width="match_parent"
android:layout_height="30dp"
android:visibility="gone"/>
...//some view down here
Now, I the code, all I needed to do it simple change the visibility to invisible (i.e. it's there, and taking the needed space, but it's unseen)
JAVA:
TextView tvSeparator = (TextView)activity.findViewById(R.id.dialogSeparator);
tvSeparator.setVisibility(View.INVISIBLE);
//Inside an activity extended class I can use 'this' instead of 'activity'.
Viola...I got the needed margin.
BTW, This solution is for LinearLayout with vertical orientation, but you can do it with different layouts.
Hope this helps.
You were probably changing the layout margin after it has been drawn. mOldTextView.invalidate() is useless. you needed to call requestLayout() on the parent to relayout the new configuration. When you moved the layout changing code before the drawing took place, everything worked fine.
TextView tv = (TextView)findViewById(R.id.item_title));
RelativeLayout.LayoutParams mRelativelp = (RelativeLayout.LayoutParams) tv
.getLayoutParams();
mRelativelp.setMargins(DptoPxConvertion(15), 0, DptoPxConvertion (15), 0);
tv.setLayoutParams(mRelativelp);
private int DptoPxConvertion(int dpValue)
{
return (int)((dpValue * mContext.getResources().getDisplayMetrics().density) + 0.5);
}
getLayoutParams() of textview should be casted to the corresponding Params based on the Parent of the textview in xml.
<RelativeLayout>
<TextView
android:id="#+id/item_title">
</RelativeLayout>
To render the same real size on different devices use DptoPxConvertion() method which I have used above. setMargin(left,top,right,bottom) params will take values in pixel not in dp. For further reference see this Link Answer

Categories

Resources