I have an image that I use as a button. It is an ImageView within a RelativeLayout. The RelativeLayout is the View that receives the touch events. While touched, I want to partially gray out the image as feedback. How do I do this?
The best way I can think of is to place another View with a black background on top of the ImageView and style it normally 100% transparent, but only 50% transparent when touched. Is there a way to style the RelativeLayout or ImageView directly without using an additional View?
Thanks in advance...
One way you could do it would be to add an onclick method for the ImageView and set a tag for it once it's grayed out and a ColorFilter to gray the view. Then you can un-gray it (provided you want the gray out to be toggled) when clicked again. Here's an example:
Add this to the xml:
<ImageView
...
android:onClick="grayOut"/>
Then in the Activity or View class
public void grayOut(View view) {
// if not grayed
if(view.getTag() != "grayed") {
view.setColorFilter(Color.argb(150,200,200,200));
view.setTag("grayed");
} else {
view.setColorFilter(null);
view.setTag("");
}
}
Use a color filter with a transparent grey color on the view when touched and remove it when you want to remove the grey color. It will be imageView.setColorFilter(transparent grey color); When you want to remove it just set the color filter to null.
Related
I set an image view on activity, but how can I remove the white space around the image view while image is .GIF?
' '
you need to have a background to the Button element, you can try and create a selector drawable and set it to the background of the button (assuming you want pres states)
for more, try reading here
Don't use imageview for png image. Use view or linerlayout.
I have a grid of 64 togglebuttons in an 8x8 form. when the app runs, it sets each togglebutton's background/drawable to a colour. this is done in the program, not the xml. my problem is that while there seems to be space between the buttons on the graphical layout of the app, when the app runs, and changes the buttons to a colour, the space disappears. this makes the buttons look like a single plate, with no definition between buttons.
What I want is to put a border on the buttons to make it clear where each button is.
the function of the buttons is to be used to indicate a musical note being pressed. when the button is pressed, the colour of the button turns from grey to light blue, and adds the note to a sequence.
So i need to be able to put a border on a togglebutton with a custom design, that changes when activated/deactivated, keeping the border in both states. i have also tried setting the max width and max height, and also setting the padding on the buttons in an attempt to seperate them.
an example of the code is as follows:
public class MainActivity extends Activity implements OnClickListener
{
ToggleButton tg1;
....
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
....
tg1 = (ToggleButton) findViewById(R.id.toggleButton1);
tg1.setOnClickListener(this);
....
tg1.setBackgroundColor(0xffcccccc); //set button grey
}
public void onClick(View v)
{
if((tg1.isChecked()))
{
tg1.setBackgroundColor(0xff00ffff); //set button blue
}
else
{
tg1.setBackgroundColor(0xffcccccc); //set button grey
}
}
}
any help is greatly appreciated.
Right way: do not call isChecked manually to change background. Use selector. You can draw 9-patch with a border or create shape (use stroke to set border color and solid to set fill color).
Or create a custom togglebutton to support desired functionality.
I write an activity for a gallery. I have ImageView elements in GridView and I see a green border on ImageView when I focus on a given element. How can I change this default color of the border? Is it possible? I don't see any method which enables it.
Any advice will be appreciated.
it's android:listSelector="#..." XML attribute in layout
I'm trying to restore the background Color of a View.
I have several selectable Views. When the user clicks one of those Views, the following code is executed and the View becomes Yellow:
View newSelection, previousSelection;
...
if(previousSelection != null) {
previousSelection.setBackgroundColor(Color.BLACK); // problem here
}
newSelection.setBackgroundColor(Color.YELLOW);
However, I want to reset the color of the previously selected View. However, I do not know which color it was (I'm setting it to Color.BLACK in the above code). I was not able to find a getBackgroundColor or similar method in the View class. If I had it, I could save the previous color and just put it back when the new View is selected.
use View.getBackground(), it returns the current 'Drawable' background of the view which can then be used in View.setBackgroundDrawable()
View theView;
Drawable originalBackground;
...
originalBackground = theView.getBackground();
theView.setBackgroundColor(Color.YELLOW);
...
theView.setBackgroundDrawable(originalBackground);
I'm not sure exactly what you are trying to accomplish but perhaps a ColorStateList would come in handy here.
You can try setting the previous color as a tag of the view.
For example
View newSelection, previousSelection;
newSelection.setTag(Color.Green);
previousSelection.setTag(Color.Black);
if(previousSelection != null) {
previousSelection.setBackgroundColor((int)previousSelection.getTag());
}
newSelection.setBackgroundColor(Color.YELLOW);
I haven't tried the code if there is an error but the flow on how to implement is there.
I've a border set around a drawable using LinearLayout (bg: rounded rectangle).
The drawable and the border is used as a tab view. I'd like to change the border color of the tab when it is selected.
How can I do this?
Color state list doesn't seem to work as the view being selected is not the shape (i.e border) but the tab. Drawable state list doesn't seem to work either as I'm trying to swivel between views, not drawables. Moreover, I can't find any "onSelectedListener" of the sort...
You need to make an OnClickListener to handle clicks, and get it to change the appropriate background:
private OnClickListener tabClick(Context mContext){
#Override
onClick(View v){
v.setBackgroundResource(R.drawable.active);
}
}
myTab.setOnClickListener(tabClick);
The solution is to call setOnTabChangeListener in the TabHost and then change everything manually.