code refactoring

Author: zagum

expandicon/build.gradle

@@ -1,5 +1,9 @@
 apply plugin: 'com.android.library'
 
+dependencies {
+ compile 'com.android.support:support-annotations:25.1.0'
+}
+
 android {
  compileSdkVersion 25
  buildToolsVersion "25.0.2"

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

@@ -10,9 +10,13 @@
 import android.graphics.Path;
 import android.graphics.Point;
 import android.os.Build;
+import android.support.annotation.IntDef;
+import android.support.annotation.RequiresApi;
 import android.util.AttributeSet;
 import android.view.View;
 import android.view.animation.DecelerateInterpolator;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
 
 import static android.graphics.Paint.ANTI_ALIAS_FLAG;
 
@@ -25,10 +29,22 @@ public class ExpandIconView extends View {
  private static final float PADDING_PROPORTION = 4f / 24f;
  private static final long DEFAULT_ANIMATION_DURATION = 150;
 
- public static final int STATE_MORE = 0;
- public static final int STATE_LESS = 1;
- private static final int STATE_INTERMEDIATE = 2;
+ @IntDef({
+ MORE,
+ 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;
+
+ @State
  private int state;
  private int width;
  private int height;
@@ -64,10 +80,10 @@ public void switchState() {
  * @param animate Indicates thaw state will be changed with animation or not
  */
  public void switchState(boolean animate) {
- if (state == STATE_MORE) {
- setState(STATE_LESS, animate);
- } else if (state == STATE_LESS) {
- setState(STATE_MORE, animate);
+ if (state == MORE) {
+ setState(LESS, animate);
+ } else if (state == LESS) {
+ setState(MORE, animate);
  } else {
  setState(getFinalStateByFraction(), animate);
  }
@@ -76,23 +92,26 @@ public void switchState(boolean animate) {
  /**
  * Set one of two states and updates view
  *
- * @param state {@link #STATE_MORE} or {@link #STATE_LESS}
+ * @param state {@link #MORE} or {@link #LESS}
  * @param animate Indicates thaw state will be changed with animation or not
+ * @throws IllegalArgumentException if {@param state} is invalid
  */
- public void setState(int state, boolean animate) {
+ public void setState(@State int state, boolean animate) {
  this.state = state;
- if (state == STATE_MORE) {
+ if (state == MORE) {
  fraction = 0f;
- } else if (state == STATE_LESS) {
+ } else if (state == LESS) {
  fraction = 1f;
+ } else {
+ throw new IllegalArgumentException("Unknown state, must be one of STATE_MORE = 0, STATE_LESS = 1");
  }
  updateArrow(animate);
  }
 
  /**
  * Set current fraction for arrow and updates view
  *
- * @param fraction Must be value from 0f to 1f {@link #STATE_MORE} state value is 0f, {@link #STATE_LESS}
+ * @param fraction Must be value from 0f to 1f {@link #MORE} state value is 0f, {@link #LESS}
  * state value is 1f
  * @throws IllegalArgumentException if fraction is less than 0f or more than 1f
  */
@@ -103,11 +122,11 @@ public void setFraction(float fraction, boolean animate) {
  if (this.fraction == fraction) return;
  this.fraction = fraction;
  if (fraction == 0f) {
- state = STATE_MORE;
+ state = MORE;
  } else if (fraction == 1f) {
- state = STATE_LESS;
+ state = LESS;
  } else {
- state = STATE_INTERMEDIATE;
+ state = INTERMEDIATE;
  }
  updateArrow(animate);
  }
@@ -129,6 +148,13 @@ public ExpandIconView(Context context, AttributeSet attrs, int defStyleAttr) {
  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();
+ }
+
  @Override
  protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
@@ -198,7 +224,7 @@ private void init() {
 
  animationSpeed = DELTA_ALPHA / animationDuration;
 
- setState(STATE_MORE, false);
+ setState(MORE, false);
  }
 
  private void updateArrow(boolean animate) {
@@ -274,11 +300,12 @@ private Point rotate(Point startPosition, double degrees) {
  return new Point(x, y);
  }
 
+ @State
  private int getFinalStateByFraction() {
  if (fraction <= .5f) {
- return STATE_MORE;
+ return MORE;
  } else {
- return STATE_LESS;
+ return LESS;
  }
  }