package com.troy.xifan.view;/*
* Copyright 2014 Chris Banes
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Build;
import android.support.v4.view.ViewCompat;
import android.support.v4.view.ViewPropertyAnimatorListenerAdapter;
import android.text.Editable;
import android.text.TextUtils;
import android.text.TextWatcher;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AnimationUtils;
import android.view.animation.Interpolator;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TextView;
import com.troy.xifan.R;
/**
* Layout which an {@link android.widget.EditText} to show a floating label when the hint is hidden
* due to the user inputting text.
*
* @see <a href="https://dribbble.com/shots/1254439--GIF-Mobile-Form-Interaction">Matt D. Smith on
* Dribble</a>
* @see <a href="http://bradfrostweb.com/blog/post/float-label-pattern/">Brad Frost's blog post</a>
*/
public class FloatLabelLayout extends LinearLayout {
private static final long ANIMATION_DURATION = 150;
private static final float DEFAULT_LABEL_PADDING_LEFT = 3f;
private static final float DEFAULT_LABEL_PADDING_TOP = 4f;
private static final float DEFAULT_LABEL_PADDING_RIGHT = 3f;
private static final float DEFAULT_LABEL_PADDING_BOTTOM = 4f;
private EditText mEditText;
private TextView mLabel;
private CharSequence mHint;
private Interpolator mInterpolator;
public FloatLabelLayout(Context context) {
this(context, null);
}
public FloatLabelLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public FloatLabelLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
setOrientation(VERTICAL);
final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.FloatLabelLayout);
int leftPadding =
a.getDimensionPixelSize(R.styleable.FloatLabelLayout_floatLabelPaddingLeft,
dipsToPix(DEFAULT_LABEL_PADDING_LEFT));
int topPadding = a.getDimensionPixelSize(R.styleable.FloatLabelLayout_floatLabelPaddingTop,
dipsToPix(DEFAULT_LABEL_PADDING_TOP));
int rightPadding =
a.getDimensionPixelSize(R.styleable.FloatLabelLayout_floatLabelPaddingRight,
dipsToPix(DEFAULT_LABEL_PADDING_RIGHT));
int bottomPadding =
a.getDimensionPixelSize(R.styleable.FloatLabelLayout_floatLabelPaddingBottom,
dipsToPix(DEFAULT_LABEL_PADDING_BOTTOM));
mHint = a.getText(R.styleable.FloatLabelLayout_floatLabelHint);
mLabel = new TextView(context);
mLabel.setPadding(leftPadding, topPadding, rightPadding, bottomPadding);
mLabel.setVisibility(INVISIBLE);
mLabel.setText(mHint);
ViewCompat.setPivotX(mLabel, 0f);
ViewCompat.setPivotY(mLabel, 0f);
mLabel.setTextAppearance(context,
a.getResourceId(R.styleable.FloatLabelLayout_floatLabelTextAppearance,
android.R.style.TextAppearance_Small));
a.recycle();
addView(mLabel, LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
mInterpolator = AnimationUtils.loadInterpolator(context,
Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP
? android.R.interpolator.fast_out_slow_in
: android.R.anim.decelerate_interpolator);
}
@Override
public final void addView(View child, int index, ViewGroup.LayoutParams params) {
if (child instanceof EditText) {
setEditText((EditText) child);
}
// Carry on adding the View...
super.addView(child, index, params);
}
private void setEditText(EditText editText) {
// If we already have an EditText, throw an exception
if (mEditText != null) {
throw new IllegalArgumentException("We already have an EditText, can only have one");
}
mEditText = editText;
// Update the label visibility with no animation
updateLabelVisibility(false);
// Add a TextWatcher so that we know when the text input has changed
mEditText.addTextChangedListener(new TextWatcher() {
@Override
public void afterTextChanged(Editable s) {
updateLabelVisibility(true);
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
});
// Add focus listener to the EditText so that we can notify the label that it is activated.
// Allows the use of a ColorStateList for the text color on the label
mEditText.setOnFocusChangeListener(new OnFocusChangeListener() {
@Override
public void onFocusChange(View view, boolean focused) {
updateLabelVisibility(true);
}
});
// If we do not have a valid hint, try and retrieve it from the EditText
if (TextUtils.isEmpty(mHint)) {
setHint(mEditText.getHint());
}
}
private void updateLabelVisibility(boolean animate) {
boolean hasText = !TextUtils.isEmpty(mEditText.getText());
boolean isFocused = mEditText.isFocused();
mLabel.setActivated(isFocused);
if (hasText || isFocused) {
// We should be showing the label so do so if it isn't already
if (mLabel.getVisibility() != VISIBLE) {
showLabel(animate);
}
} else {
// We should not be showing the label so hide it
if (mLabel.getVisibility() == VISIBLE) {
hideLabel(animate);
}
}
}
/**
* @return the {@link android.widget.EditText} text input
*/
public EditText getEditText() {
return mEditText;
}
/**
* @return the {@link android.widget.TextView} label
*/
public TextView getLabel() {
return mLabel;
}
/**
* Set the hint to be displayed in the floating label
*/
public void setHint(CharSequence hint) {
mHint = hint;
mLabel.setText(hint);
}
/**
* Show the label
*/
private void showLabel(boolean animate) {
if (animate) {
mLabel.setVisibility(View.VISIBLE);
ViewCompat.setTranslationY(mLabel, mLabel.getHeight());
float scale = mEditText.getTextSize() / mLabel.getTextSize();
ViewCompat.setScaleX(mLabel, scale);
ViewCompat.setScaleY(mLabel, scale);
ViewCompat.animate(mLabel)
.translationY(0f)
.scaleY(1f)
.scaleX(1f)
.setDuration(ANIMATION_DURATION)
.setListener(null)
.setInterpolator(mInterpolator)
.start();
} else {
mLabel.setVisibility(VISIBLE);
}
mEditText.setHint(null);
}
/**
* Hide the label
*/
private void hideLabel(boolean animate) {
if (animate) {
float scale = mEditText.getTextSize() / mLabel.getTextSize();
ViewCompat.setScaleX(mLabel, 1f);
ViewCompat.setScaleY(mLabel, 1f);
ViewCompat.setTranslationY(mLabel, 0f);
ViewCompat.animate(mLabel)
.translationY(mLabel.getHeight())
.setDuration(ANIMATION_DURATION)
.scaleX(scale)
.scaleY(scale)
.setListener(new ViewPropertyAnimatorListenerAdapter() {
@Override
public void onAnimationEnd(View view) {
mLabel.setVisibility(INVISIBLE);
mEditText.setHint(mHint);
}
})
.setInterpolator(mInterpolator)
.start();
} else {
mLabel.setVisibility(INVISIBLE);
mEditText.setHint(mHint);
}
}
/**
* Helper method to convert dips to pixels.
*/
private int dipsToPix(float dps) {
return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dps,
getResources().getDisplayMetrics());
}
}