Chia sẻ giải pháp tổng quát của tôi để xử lý các sự kiện nhấp và chạm có thể vẽ được của TextView.
Đầu tiên chúng ta cần một trình xử lý sự kiện cảm ứng:
/**
* Handles compound drawable touch events.
* Will intercept every event that happened inside (calculated) compound drawable bounds, extended by fuzz.
* @see TextView#getCompoundDrawables()
* @see TextView#setCompoundDrawablesRelativeWithIntrinsicBounds(int, int, int, int)
*/
public abstract class CompoundDrawableTouchListener implements View.OnTouchListener {
private final String LOG_TAG = "CmpDrawableTouch";
private final int fuzz;
public static final int LEFT = 0;
public static final int TOP = 1;
public static final int RIGHT = 2;
public static final int BOTTOM = 3;
private static final int[] DRAWABLE_INDEXES = {LEFT, TOP, RIGHT, BOTTOM};
/**
* Default constructor
*/
public CompoundDrawableTouchListener() {
this(0);
}
/**
* Constructor with fuzz
* @param fuzz desired fuzz in px
*/
public CompoundDrawableTouchListener(int fuzz) {
this.fuzz = fuzz;
}
@Override
public boolean onTouch(View view, MotionEvent event) {
if (!(view instanceof TextView)) {
Log.e(LOG_TAG, "attached view is not instance of TextView");
return false;
}
TextView textView = (TextView) view;
Drawable[] drawables = textView.getCompoundDrawables();
int x = (int) event.getX();
int y = (int) event.getY();
for (int i : DRAWABLE_INDEXES) {
if (drawables[i] == null) continue;
Rect bounds = getRelativeBounds(i, drawables[i], textView);
Rect fuzzedBounds = addFuzz(bounds);
if (fuzzedBounds.contains(x, y)) {
MotionEvent relativeEvent = MotionEvent.obtain(
event.getDownTime(),
event.getEventTime(),
event.getAction(),
event.getX() - bounds.left,
event.getY() - bounds.top,
event.getMetaState());
return onDrawableTouch(view, i, bounds, relativeEvent);
}
}
return false;
}
/**
* Calculates compound drawable bounds relative to wrapping view
* @param index compound drawable index
* @param drawable the drawable
* @param view wrapping view
* @return {@link Rect} with relative bounds
*/
private Rect getRelativeBounds(int index, @NonNull Drawable drawable, View view) {
Rect drawableBounds = drawable.getBounds();
Rect bounds = new Rect();
switch (index) {
case LEFT:
bounds.offsetTo(view.getPaddingLeft(),
view.getHeight() / 2 - bounds.height() / 2);
break;
case TOP:
bounds.offsetTo(view.getWidth() / 2 - bounds.width() / 2,
view.getPaddingTop());
break;
case RIGHT:
bounds.offsetTo(view.getWidth() - view.getPaddingRight() - bounds.width(),
view.getHeight() / 2 - bounds.height() / 2);
break;
case BOTTOM:
bounds.offsetTo(view.getWidth() / 2 - bounds.width() / 2,
view.getHeight() - view.getPaddingBottom() - bounds.height());
break;
}
return bounds;
}
/**
* Expands {@link Rect} by given value in every direction relative to its center
* @param source given {@link Rect}
* @return result {@link Rect}
*/
private Rect addFuzz(Rect source) {
Rect result = new Rect();
result.left = source.left - fuzz;
result.right = source.right + fuzz;
result.top = source.top - fuzz;
result.bottom = source.bottom + fuzz;
return result;
}
/**
* Compound drawable touch-event handler
* @param v wrapping view
* @param drawableIndex index of compound drawable which recicved the event
* @param drawableBounds {@link Rect} with compound drawable bounds relative to wrapping view.
* Fuzz not included
* @param event event with coordinated relative to wrapping view - i.e. within {@code drawableBounds}.
* If using fuzz, may return negative coordinates.
*/
protected abstract boolean onDrawableTouch(View v, int drawableIndex, Rect drawableBounds, MotionEvent event);
}
Giờ đây, bạn có thể xử lý bất kỳ sự kiện chạm nào trên bất kỳ hợp chất có thể vẽ nào của bất kỳ TextView nào bạn thích theo cách này:
textView1.setOnTouchListener(new CompoundDrawableTouchListener() {
@Override
protected void onDrawableTouch(View v, int drawableIndex, Rect drawableBounds, MotionEvent event) {
switch(v.getId()) {
case R.id.textView1:
switch(drawableIndex) {
case CompoundDrawableTouchListener.RIGHT:
doStuff();
break;
}
break;
}
}
});
Chỉ quan tâm đến nhấp chuột? Chỉ cần lọc ra bằng hành động MotionEvent:
/**
* Handles compound drawable click events.
* @see TextView#getCompoundDrawables()
* @see TextView#setCompoundDrawablesRelativeWithIntrinsicBounds(int, int, int, int)
* @see CompoundDrawableTouchListener
*/
public abstract class CompoundDrawableClickListener extends CompoundDrawableTouchListener {
/**
* Default constructor
*/
public CompoundDrawableClickListener() {
super();
}
/**
* Constructor with fuzz
* @param fuzz desired fuzz in px
*/
public CompoundDrawableClickListener(int fuzz) {
super(fuzz);
}
@Override
protected void onDrawableTouch(View v, int drawableIndex, Rect drawableBounds, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_UP) onDrawableClick(v, drawableIndex);
return true;
}
/**
* Compound drawable touch-event handler
* @param v wrapping view
* @param drawableIndex index of compound drawable which recicved the event
*/
protected abstract void onDrawableClick(View v, int drawableIndex);
}
Một lần nữa, chúng ta có thể dễ dàng xử lý các nhấp chuột trên bất kỳ hợp chất có thể rút ra của bất kỳ TextView nào:
textView1.setOnTouchListener(new CompoundDrawableClickListener() {
@Override
protected void onDrawableClick(View v, int drawableIndex) {
switch(v.getId()) {
case R.id.textView1:
switch(drawableIndex) {
case CompoundDrawableTouchListener.RIGHT:
doStuff();
break;
}
break;
}
}
});
Hy vọng bạn thích nó như tôi đã làm. Tôi sẽ cố gắng giữ cho nó được cập nhật ở đây và trong ý chính liên quan nếu có gì thay đổi.
