19.Android 清除按钮EditText - AIEditText

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实现思路

1.继承AppCompatEditText类。
2.读取图片，每次都通过setCompoundDrawables将图片设置到EditText的右边。
3.实现OnFocusChangeListener接口，每次获得焦点的时候，进行一次文本的判断，如果有文本，显示图片；没有文本，隐藏图片。
4.实现View.OnTouchListener接口，每次onTouch的时候，判断是否点击到了图片，进行文本的清空。
5.实现TextWatcher接口，通过判断文本的长度，来决定图片是否显示。

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继承AppCompatEditText类

    public AIEditText(Context context) {        super(context);        this.init(context);    }    public AIEditText(Context context, AttributeSet attrs) {        super(context, attrs);        this.init(context);    }    public AIEditText(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        this.init(context);    }

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setCompoundDrawables设置图片

从TextView继承下来的方法setCompoundDrawables。

EditText也是TextView的子类，AppCompatEditText又是EditText的子类。

setCompoundDrawables(@Nullable Drawable left, @Nullable Drawable top,
@Nullable Drawable right, @Nullable Drawable bottom)

    /**     * @param context     */    private void init(Context context) {        Drawable drawable = ContextCompat.getDrawable(context, R.drawable.abc_ic_clear_mtrl_alpha);        Drawable wrappedDrawable = DrawableCompat.wrap(drawable);        DrawableCompat.setTint(wrappedDrawable, super.getCurrentHintTextColor());        this.mClearDrawable = wrappedDrawable;        this.mClearDrawable.setBounds(0, 0, this.mClearDrawable.getIntrinsicHeight(), this.mClearDrawable.getIntrinsicHeight());        this.setClearDrawableVisible(false);        super.setOnTouchListener(this);        super.setOnFocusChangeListener(this);        this.addTextChangedListener(this);    }    private void setClearDrawableVisible(boolean visible) {        this.mClearDrawable.setVisible(visible, false);        final Drawable[] compoundDrawables = this.getCompoundDrawables();        this.setCompoundDrawables(compoundDrawables[0], compoundDrawables[1], visible ? this.mClearDrawable : null, compoundDrawables[3]);    }

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实现OnFocusChangeListener接口

每次获得焦点的时候，进行一次文本的判断，如果有文本，显示图片；没有文本，隐藏图片。

    /**     * Called when the focus state of a view has changed.     *     * @param v        The view whose state has changed.     * @param hasFocus The new focus state of v.     */    @Override    public void onFocusChange(View v, boolean hasFocus) {        if (hasFocus) {            this.setClearDrawableVisible(this.getText().length() > 0);        } else {            this.setClearDrawableVisible(false);        }        if (this.mOnFocusChangeListener != null)            this.mOnFocusChangeListener.onFocusChange(v, hasFocus);    }

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实现View.OnTouchListener接口

每次onTouch的时候，判断是否点击到了图片，进行文本的清空。

    /**     * @param v     The view the touch event has been dispatched to.     * @param event The MotionEvent object containing full information about     *              the event.     * @return True if the listener has consumed the event, false otherwise.     */    @Override    public boolean onTouch(View v, MotionEvent event) {        final int x = (int) event.getX();        /**         * x > ableEditWidth (totalWidth - paddingRight - clearDrawableWidth )         * x > ableEditWidth == clearDrawable_X         * so , when clearDrawable is visible and onClick it.         */        if (this.mClearDrawable.isVisible() && x > this.getWidth() - this.getPaddingRight() - this.mClearDrawable.getIntrinsicWidth()) {            if (event.getAction() == MotionEvent.ACTION_UP) {                this.setError(null);                this.setText("");            }            return true;        }        return this.mOnTouchListener != null && this.mOnTouchListener.onTouch(v, event);    }

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实现TextWatcher接口

通过判断文本的长度，来决定图片是否显示。

    /**     * @param text         The text the TextView is displaying     * @param start        The offset of the start of the range of the text that was     *                     modified     * @param lengthBefore The length of the former text that has been replaced     * @param lengthAfter  The length of the replacement modified text     */    @Override    public void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {        if (isFocused()) this.setClearDrawableVisible(text.length() > 0);    }

AIEditText源码

public class AIEditText extends AppCompatEditText implements View.OnTouchListener, View.OnFocusChangeListener, TextWatcher {    private Drawable mClearDrawable;    private OnFocusChangeListener mOnFocusChangeListener;    private OnTouchListener mOnTouchListener;    public AIEditText(Context context) {        super(context);        this.init(context);    }    public AIEditText(Context context, AttributeSet attrs) {        super(context, attrs);        this.init(context);    }    public AIEditText(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        this.init(context);    }    /**     * Register a callback to be invoked when focus of this view changed.     *     * @param l The callback that will run.     */    @Override    public void setOnFocusChangeListener(OnFocusChangeListener l) {        this.mOnFocusChangeListener = l;    }    /**     * Register a callback to be invoked when a touch event is sent to this view.     *     * @param l the touch listener to attach to this view     */    @Override    public void setOnTouchListener(OnTouchListener l) {        this.mOnTouchListener = l;    }    /**     * @param context     */    private void init(Context context) {        Drawable drawable = ContextCompat.getDrawable(context, R.drawable.abc_ic_clear_mtrl_alpha);        Drawable wrappedDrawable = DrawableCompat.wrap(drawable);        DrawableCompat.setTint(wrappedDrawable, super.getCurrentHintTextColor());        this.mClearDrawable = wrappedDrawable;        this.mClearDrawable.setBounds(0, 0, this.mClearDrawable.getIntrinsicHeight(), this.mClearDrawable.getIntrinsicHeight());        this.setClearDrawableVisible(false);        super.setOnTouchListener(this);        super.setOnFocusChangeListener(this);        this.addTextChangedListener(this);    }    private void setClearDrawableVisible(boolean visible) {        this.mClearDrawable.setVisible(visible, false);        final Drawable[] compoundDrawables = this.getCompoundDrawables();        this.setCompoundDrawables(compoundDrawables[0], compoundDrawables[1], visible ? this.mClearDrawable : null, compoundDrawables[3]);    }    /**     * @param v     The view the touch event has been dispatched to.     * @param event The MotionEvent object containing full information about     *              the event.     * @return True if the listener has consumed the event, false otherwise.     */    @Override    public boolean onTouch(View v, MotionEvent event) {        final int x = (int) event.getX();        /**         * x > ableEditWidth (totalWidth - paddingRight - clearDrawableWidth )         * x > ableEditWidth == clearDrawable_X         * so , when clearDrawable is visible and onClick it.         */        if (this.mClearDrawable.isVisible() && x > this.getWidth() - this.getPaddingRight() - this.mClearDrawable.getIntrinsicWidth()) {            if (event.getAction() == MotionEvent.ACTION_UP) {                this.setError(null);                this.setText("");            }            return true;        }        return this.mOnTouchListener != null && this.mOnTouchListener.onTouch(v, event);    }    /**     * Called when the focus state of a view has changed.     *     * @param v        The view whose state has changed.     * @param hasFocus The new focus state of v.     */    @Override    public void onFocusChange(View v, boolean hasFocus) {        if (hasFocus) {            this.setClearDrawableVisible(this.getText().length() > 0);        } else {            this.setClearDrawableVisible(false);        }        if (this.mOnFocusChangeListener != null)            this.mOnFocusChangeListener.onFocusChange(v, hasFocus);    }    /**     * @param text         The text the TextView is displaying     * @param start        The offset of the start of the range of the text that was     *                     modified     * @param lengthBefore The length of the former text that has been replaced     * @param lengthAfter  The length of the replacement modified text     */    @Override    public void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {        if (isFocused()) this.setClearDrawableVisible(text.length() > 0);    }    /**     * @param s     * @param start     * @param count     * @param after     */    @Override    public void beforeTextChanged(CharSequence s, int start, int count, int after) {    }    /**     * @param s     */    @Override    public void afterTextChanged(Editable s) {    }}

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AIEditText效果图

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Github传送门

https://github.com/CaMnter/AIEditText