Merge pull request #4 from arychagov/master

enhanced ExpandIconView code to be more pretty and faster

Author: Zagumennyi Evgenii

expandicon/src/main/java/com/github/zagum/expandicon/ExpandIconView.java

@@ -10,11 +10,14 @@
 import android.graphics.Path;
 import android.graphics.Point;
 import android.os.Build;
+import android.support.annotation.FloatRange;
 import android.support.annotation.IntDef;
-import android.support.annotation.RequiresApi;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.util.AttributeSet;
 import android.view.View;
 import android.view.animation.DecelerateInterpolator;
+
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 
@@ -34,42 +37,87 @@ public class ExpandIconView extends View {
  LESS,
  INTERMEDIATE
  })
-
  @Retention(RetentionPolicy.SOURCE)
-
  public @interface State {
  }
 
  public static final int MORE = 0;
  public static final int LESS = 1;
- private static final int INTERMEDIATE = 2;
+ public static final int INTERMEDIATE = 2;
 
  @State
  private int state;
- private int width;
- private int height;
- private int arrowWidth;
  private float alpha = MORE_STATE_ALPHA;
  private float centerTranslation = 0f;
+ @FloatRange(from = 0.f, to = 1.f)
  private float fraction = 0f;
- private float animationSpeed;
- private boolean useDefaultPadding;
+ private final float animationSpeed;
 
- private boolean roundedCorners = false;
  private boolean switchColor = false;
- private long animationDuration = DEFAULT_ANIMATION_DURATION;
  private int color = Color.BLACK;
- private int colorMore = Color.BLACK;
- private int colorLess = Color.RED;
+ private final int colorMore;
+ private final int colorLess;
+
+ @NonNull
+ private final Paint paint;
+ private final Point left = new Point();
+ private final Point right = new Point();
+ private final Point center = new Point();
+ private final Point tempLeft = new Point();
+ private final Point tempRight = new Point();
+
+ private final boolean useDefaultPadding;
  private int padding;
 
- private Paint paint;
- private Point left;
- private Point right;
- private Point center;
  private final Path path = new Path();
+ @Nullable
  private ValueAnimator arrowAnimator;
 
+ public ExpandIconView(@NonNull Context context) {
+ this(context, null);
+ }
+
+ public ExpandIconView(@NonNull Context context, @Nullable AttributeSet attrs) {
+ this(context, attrs, 0);
+ }
+
+ public ExpandIconView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
+ super(context, attrs, defStyleAttr);
+
+ TypedArray array = getContext().getTheme().obtainStyledAttributes(attrs,
+ R.styleable.ExpandIconView,
+ 0, 0);
+
+ final boolean roundedCorners;
+ final long animationDuration;
+ try {
+ roundedCorners = array.getBoolean(R.styleable.ExpandIconView_roundedCorners, false);
+ switchColor = array.getBoolean(R.styleable.ExpandIconView_switchColor, false);
+ color = array.getColor(R.styleable.ExpandIconView_color, Color.BLACK);
+ colorMore = array.getColor(R.styleable.ExpandIconView_colorMore, Color.BLACK);
+ colorLess = array.getColor(R.styleable.ExpandIconView_colorLess, Color.BLACK);
+ animationDuration = array.getInteger(R.styleable.ExpandIconView_animationDuration, (int) DEFAULT_ANIMATION_DURATION);
+ padding = array.getDimensionPixelSize(R.styleable.ExpandIconView_eiv_padding, -1);
+ useDefaultPadding = (padding == -1);
+ } finally {
+ array.recycle();
+ }
+
+ {
+ paint = new Paint(ANTI_ALIAS_FLAG);
+ paint.setColor(color);
+ paint.setStyle(Paint.Style.STROKE);
+ paint.setDither(true);
+ if (roundedCorners) {
+ paint.setStrokeJoin(Paint.Join.ROUND);
+ paint.setStrokeCap(Paint.Cap.ROUND);
+ }
+ }
+
+ animationSpeed = DELTA_ALPHA / animationDuration;
+ setState(MORE, false);
+ }
+
  public void switchState() {
  switchState(true);
  }
@@ -80,13 +128,21 @@ public void switchState() {
  * @param animate Indicates thaw state will be changed with animation or not
  */
  public void switchState(boolean animate) {
- if (state == MORE) {
- setState(LESS, animate);
- } else if (state == LESS) {
- setState(MORE, animate);
- } else {
- setState(getFinalStateByFraction(), animate);
+ final int newState;
+ switch (state) {
+ case MORE:
+ newState = LESS;
+ break;
+ case LESS:
+ newState = MORE;
+ break;
+ case INTERMEDIATE:
+ newState = getFinalStateByFraction();
+ break;
+ default:
+ throw new IllegalArgumentException("Unknown state [" + state + "]");
  }
+ setState(newState, animate);
  }
 
  /**
@@ -115,11 +171,15 @@ public void setState(@State int state, boolean animate) {
  * state value is 1f
  * @throws IllegalArgumentException if fraction is less than 0f or more than 1f
  */
- public void setFraction(float fraction, boolean animate) {
+ public void setFraction(@FloatRange(from = 0.f, to = 1.f) float fraction, boolean animate) {
  if (fraction < 0f || fraction > 1f) {
  throw new IllegalArgumentException("Fraction value must be from 0 to 1f, fraction=" + fraction);
  }
- if (this.fraction == fraction) return;
+
+ if (this.fraction == fraction) {
+ return;
+ }
+
  this.fraction = fraction;
  if (fraction == 0f) {
  state = MORE;
@@ -128,31 +188,8 @@ public void setFraction(float fraction, boolean animate) {
  } else {
  state = INTERMEDIATE;
  }
- updateArrow(animate);
- }
-
- public ExpandIconView(Context context) {
- super(context);
- init();
- }
-
- public ExpandIconView(Context context, AttributeSet attrs) {
- super(context, attrs);
- readAttributes(attrs);
- init();
- }
-
- public ExpandIconView(Context context, AttributeSet attrs, int defStyleAttr) {
- super(context, attrs, defStyleAttr);
- readAttributes(attrs);
- init();
- }
 
- @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
- public ExpandIconView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
- super(context, attrs, defStyleAttr, defStyleRes);
- readAttributes(attrs);
- init();
+ updateArrow(animate);
  }
 
  @Override
@@ -165,35 +202,15 @@ protected void onDraw(Canvas canvas) {
  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
  super.onMeasure(widthMeasureSpec, heightMeasureSpec);
- width = getMeasuredWidth();
- height = getMeasuredHeight();
  calculateArrowMetrics();
  updateArrowPath();
  }
 
- private void readAttributes(AttributeSet attrs) {
- TypedArray array = getContext().getTheme().obtainStyledAttributes(
- attrs,
- R.styleable.ExpandIconView,
- 0, 0);
-
- try {
- roundedCorners = array.getBoolean(R.styleable.ExpandIconView_eiv_roundedCorners, false);
- switchColor = array.getBoolean(R.styleable.ExpandIconView_eiv_switchColor, false);
- color = array.getColor(R.styleable.ExpandIconView_eiv_color, Color.BLACK);
- colorMore = array.getColor(R.styleable.ExpandIconView_eiv_colorMore, Color.BLACK);
- colorLess = array.getColor(R.styleable.ExpandIconView_eiv_colorLess, Color.BLACK);
- animationDuration = array.getInteger(R.styleable.ExpandIconView_eiv_animationDuration, (int) DEFAULT_ANIMATION_DURATION);
- padding = array.getDimensionPixelSize(R.styleable.ExpandIconView_eiv_padding, -1);
- if (padding == -1) useDefaultPadding = true;
- } finally {
- array.recycle();
- }
- }
-
  private void calculateArrowMetrics() {
- int arrowMaxHeight = height - 2 * padding;
- arrowWidth = width - 2 * padding;
+ final int width = getMeasuredWidth();
+ final int height = getMeasuredHeight();
+ final int arrowMaxHeight = height - 2 * padding;
+ int arrowWidth = width - 2 * padding;
  arrowWidth = arrowMaxHeight >= arrowWidth ? arrowWidth : arrowMaxHeight;
 
  if (useDefaultPadding) {
@@ -208,25 +225,6 @@ private void calculateArrowMetrics() {
  right.set(center.x + arrowWidth / 2, center.y);
  }
 
- private void init() {
- paint = new Paint(ANTI_ALIAS_FLAG);
- paint.setColor(color);
- paint.setStyle(Paint.Style.STROKE);
- paint.setDither(true);
- if (roundedCorners) {
- paint.setStrokeJoin(Paint.Join.ROUND);
- paint.setStrokeCap(Paint.Cap.ROUND);
- }
-
- left = new Point();
- right = new Point();
- center = new Point();
-
- animationSpeed = DELTA_ALPHA / animationDuration;
-
- setState(MORE, false);
- }
-
  private void updateArrow(boolean animate) {
  float toAlpha = MORE_STATE_ALPHA + (fraction * DELTA_ALPHA);
  if (animate) {
@@ -245,21 +243,22 @@ private void updateArrow(boolean animate) {
  private void updateArrowPath() {
  path.reset();
  if (left != null && right != null) {
- Point currLeft = rotate(left, -alpha);
- Point currRight = rotate(right, alpha);
- centerTranslation = (center.y - currLeft.y) / 2;
- path.moveTo(currLeft.x, currLeft.y);
+ rotate(left, -alpha, tempLeft);
+ rotate(right, alpha, tempRight);
+ centerTranslation = (center.y - tempLeft.y) / 2;
+ path.moveTo(tempLeft.x, tempLeft.y);
  path.lineTo(center.x, center.y);
- path.lineTo(currRight.x, currRight.y);
+ path.lineTo(tempRight.x, tempRight.y);
  }
  }
 
  private void animateArrow(float toAlpha) {
  cancelAnimation();
- final ArgbEvaluator colorEvaluator = new ArgbEvaluator();
 
- arrowAnimator = ValueAnimator.ofFloat(alpha, toAlpha);
- arrowAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
+ final ValueAnimator valueAnimator = ValueAnimator.ofFloat(alpha, toAlpha);
+ valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
+ private final ArgbEvaluator colorEvaluator = new ArgbEvaluator();
+
  @Override
  public void onAnimationUpdate(ValueAnimator valueAnimator) {
  alpha = (float) valueAnimator.getAnimatedValue();
@@ -270,9 +269,11 @@ public void onAnimationUpdate(ValueAnimator valueAnimator) {
  postInvalidateOnAnimationCompat();
  }
  });
- arrowAnimator.setInterpolator(new DecelerateInterpolator());
- arrowAnimator.setDuration(calculateAnimationDuration(toAlpha));
- arrowAnimator.start();
+ valueAnimator.setInterpolator(new DecelerateInterpolator());
+ valueAnimator.setDuration(calculateAnimationDuration(toAlpha));
+ valueAnimator.start();
+
+ arrowAnimator = valueAnimator;
  }
 
  private void cancelAnimation() {
@@ -281,7 +282,7 @@ private void cancelAnimation() {
  }
  }
 
- private void updateColor(ArgbEvaluator colorEvaluator) {
+ private void updateColor(@NonNull ArgbEvaluator colorEvaluator) {
  color = (int) colorEvaluator.evaluate((alpha + 45f) / 90f, colorMore, colorLess);
  paint.setColor(color);
  }
@@ -290,14 +291,15 @@ private long calculateAnimationDuration(float toAlpha) {
  return (long) (Math.abs(toAlpha - alpha) / animationSpeed);
  }
 
- private Point rotate(Point startPosition, double degrees) {
+ private void rotate(@NonNull Point startPosition, double degrees, @NonNull Point target) {
  double angle = Math.toRadians(degrees);
  int x = (int) (center.x + (startPosition.x - center.x) * Math.cos(angle) -
  (startPosition.y - center.y) * Math.sin(angle));
 
  int y = (int) (center.y + (startPosition.x - center.x) * Math.sin(angle) +
  (startPosition.y - center.y) * Math.cos(angle));
- return new Point(x, y);
+
+ target.set(x, y);
  }
 
  @State