package cn.zhaiyifan.interestingtitlebar;
import android.content.Context;
import android.content.res.ColorStateList;
import android.graphics.Color;
import android.graphics.PorterDuff;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.view.View;
import android.widget.AbsListView;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.LinkedList;
/**
* Immersive title bar with scroll animation
* <p/>
* Created by markzhai on 2015/1/12.
*/
public class CustomTitleBar extends ImmersiveTitleBar implements ScrollAnimInterface {
private static final String TAG = "CustomTitleBar";
// ============================================================================
// Scroll animation
// ============================================================================
// store original color
private static final int ORIGIN_COLOR = -12345;
private boolean mTransparentEnabled = false;
// start position of fading animation
private int mStartFadePosition = 80;
// end position of fading animation
private int mEndFadePosition = 380;
// Max alpha, by default 247(0.97*255)
private int mMaxAlpha = 247;
// fade area
private int mFadeDuration = mEndFadePosition - mStartFadePosition;
// text shadow when completely transparent
private float mShadowRadius = 0;
private int mBarTitleTextShadowColor;
// View needs to do gradual change during scroll animation
private LinkedList<View> mFadeViewList = null;
private TextView mTitleTextView = null;
private ColorStateList mOriginBarTitleColor = null;
public CustomTitleBar(Context context, AttributeSet attrs) {
super(context, attrs, 0);
}
/**
* Set transparent title bar anim.
*
* @param enabled whether to open anim
*/
public void setTransparentEnabled(boolean enabled) {
setTransparentEnabled(enabled, mStartFadePosition, mEndFadePosition, mMaxAlpha);
}
/**
* Set transparent title bar anim.
*
* @param enabled whether to open anim
* @param start start position of fading animation
* @param end end position of fading animation
*/
public void setTransparentEnabled(boolean enabled, int start, int end) {
setTransparentEnabled(enabled, start, end, mMaxAlpha);
}
/**
* Set transparent title bar anim.
*
* @param enabled whether to open anim
* @param start start position of fading animation
* @param end end position of fading animation
* @param maxAlpha max alpha(0-255)
*/
public void setTransparentEnabled(boolean enabled, int start, int end, int maxAlpha) {
mTransparentEnabled = enabled;
if (mTransparentEnabled) {
mStartFadePosition = start;
mEndFadePosition = end;
mMaxAlpha = maxAlpha;
mFadeDuration = mEndFadePosition - mStartFadePosition;
}
}
/**
* Add view that needs gradual change
*/
public void addViewToFadeList(View view) {
if (mFadeViewList == null) {
mFadeViewList = new LinkedList<View>();
}
if (view != null) {
mFadeViewList.add(view);
}
}
/**
* remove view that has been added by addViewToFadeList
*/
public void removeViewFromFadeList(View view) {
if (mFadeViewList != null && view != null) {
mFadeViewList.remove(view);
}
}
public void setTitle(String title) {
if (!TextUtils.isEmpty(title) && mTitleTextView != null) {
mTitleTextView.setText(title);
}
}
public void setTitleTextView(TextView textView) {
mTitleTextView = textView;
if (mTitleTextView != null) {
mOriginBarTitleColor = mTitleTextView.getTextColors();
}
}
public void setTextShadowColor(int color) {
mBarTitleTextShadowColor = color;
}
private void setTitleBarTranslate(int alpha) {
if (getBackground() == null) {
return;
}
getBackground().mutate().setAlpha(alpha);
if (mFadeViewList == null || mTitleTextView == null) {
return;
}
if (alpha > 0) {
setTitleBarShadowLayer(0);
}
if (alpha >= mMaxAlpha) {
setTitleBarColor(ORIGIN_COLOR);
} else {
setTitleBarColor(interpolateColor(Color.WHITE, mOriginBarTitleColor.getDefaultColor(), alpha, mMaxAlpha));
if (alpha == 0) {
setTitleBarShadowLayer(1f);
}
}
}
private void setTitleBarColor(int color) {
for (View view : mFadeViewList) {
setViewColor(view, color);
}
}
private void setViewColor(View view, int color) {
if (view == null || view.getVisibility() != VISIBLE) {
return;
}
if (view instanceof TextView) {
setViewColor((TextView) view, color);
}
if (view instanceof ImageView) {
setViewColor((ImageView) view, color);
}
}
private void setViewColor(TextView view, int color) {
if (color == ORIGIN_COLOR) {
view.setTextColor(mOriginBarTitleColor);
if (view.getBackground() != null) {
view.getBackground().clearColorFilter();
}
} else {
view.setTextColor(color);
if (view.getBackground() != null) {
view.getBackground().setColorFilter(color, PorterDuff.Mode.SRC_ATOP);
}
}
}
private void setViewColor(ImageView view, int color) {
if (color == ORIGIN_COLOR) {
view.clearColorFilter();
} else {
view.setColorFilter(color, PorterDuff.Mode.SRC_ATOP);
}
}
private void setTitleBarShadowLayer(float radius) {
if (mShadowRadius != radius) {
mShadowRadius = radius;
for (View view : mFadeViewList) {
if (view instanceof TextView) {
((TextView) view).setShadowLayer(mShadowRadius, 0, 1, mBarTitleTextShadowColor);
}
}
}
}
/**
* onScroll callback interface for ListView
*/
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int endFadeItem) {
if (mTransparentEnabled && firstVisibleItem <= endFadeItem) {
View v = view.getChildAt(0);
// Top of visible window, originally 0, turn to negative when scroll to lower position
int top = (v == null) ? 0 : v.getTop();
// distance from top of current window to ending position of fade
int delta = top + mEndFadePosition;
setTitleBarTranslate(interpolate(delta));
}
}
/**
* onScroll callback interface for ScrollView
*/
@Override
public void onScroll(int y) {
if (mTransparentEnabled) {
setTitleBarTranslate(interpolate(mEndFadePosition - y));
}
}
/**
* @param delta distance to ending position
* @return alpha value at current position
*/
private int interpolate(int delta) {
if (delta > mFadeDuration) {
return 0;
} else if (delta <= 0) {
return mMaxAlpha;
} else {
float temp = ((float) delta) / mFadeDuration;
return (int) ((1 - temp) * mMaxAlpha);
}
}
public static int interpolateColor(int colorFrom, int colorTo, int posFrom, int posTo) {
float delta = posTo - posFrom;
int red = (int) ((Color.red(colorFrom) - Color.red(colorTo)) * delta / posTo + Color.red(colorTo));
int green = (int) ((Color.green(colorFrom) - Color.green(colorTo)) * delta / posTo + Color.green(colorTo));
int blue = (int) ((Color.blue(colorFrom) - Color.blue(colorTo)) * delta / posTo) + Color.blue(colorTo);
return Color.argb(255, red, green, blue);
}
}
