I need to customize a seek bar in such a way that, at pre determined time say , 30sec, I should have a dot on the seek bar. This duration varies for each and every video, so
Here're some possibilities:
SeekBar one. Will not explain it here in details, because it's trivial android-layout task;Extend SeekBar, like the following (refer to this good explanation about custom views):
/**
* Seek bar with dots on it on specific time / percent
*/
public class DottedSeekBar extends SeekBar {
/** Int values which corresponds to dots */
private int[] mDotsPositions = null;
/** Drawable for dot */
private Bitmap mDotBitmap = null;
public DottedSeekBar(final Context context) {
super(context);
init(null);
}
public DottedSeekBar(final Context context, final AttributeSet attrs) {
super(context, attrs);
init(attrs);
}
public DottedSeekBar(final Context context, final AttributeSet attrs, final int defStyle) {
super(context, attrs, defStyle);
init(attrs);
}
/**
* Initializes Seek bar extended attributes from xml
*
* @param attributeSet {@link AttributeSet}
*/
private void init(final AttributeSet attributeSet) {
final TypedArray attrsArray = getContext().obtainStyledAttributes(attributeSet, R.styleable.DottedSeekBar, 0, 0);
final int dotsArrayResource = attrsArray.getResourceId(R.styleable.DottedSeekBar_dots_positions, 0);
if (0 != dotsArrayResource) {
mDotsPositions = getResources().getIntArray(dotsArrayResource);
}
final int dotDrawableId = attrsArray.getResourceId(R.styleable.DottedSeekBar_dots_drawable, 0);
if (0 != dotDrawableId) {
mDotBitmap = BitmapFactory.decodeResource(getResources(), dotDrawableId);
}
}
/**
* @param dots to be displayed on this SeekBar
*/
public void setDots(final int[] dots) {
mDotsPositions = dots;
invalidate();
}
/**
* @param dotsResource resource id to be used for dots drawing
*/
public void setDotsDrawable(final int dotsResource) {
mDotBitmap = BitmapFactory.decodeResource(getResources(), dotsResource);
invalidate();
}
@Override
protected synchronized void onDraw(final Canvas canvas) {
super.onDraw(canvas);
final int width = getMeasuredWidth();
final int step = width / getMax();
if (null != mDotsPositions && 0 != mDotsPositions.length && null != mDotBitmap) {
// draw dots if we have ones
for (int position : mDotsPositions) {
canvas.drawBitmap(mDotBitmap, position * step, 0, null);
}
}
}
}
Don't forget about custom attrs in res/values/attrs.xml:
And using the following code:
setContentView(R.layout.main);
final DottedSeekBar bar = (DottedSeekBar) findViewById(R.id.seekBar);
bar.setDots(new int[] {25, 50, 75});
bar.setDotsDrawable(R.drawable.dot);
with main.xml layout:
or just single main.xml:
You could obtain the following image:

Refer to this example for more ideas;
Regarding putting dots on specific 'time': SeekBar is not about time, so it's up to You to provide any time-related logic.