android 旋轉圓環菜單

package com.szugyi.circlemenu.view;

/*
* Copyright 2013 Csaba Szugyiczki
*
* 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.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;

import com.szugyi.circlemenu.R;

/**
*
* @author Szugyi
* Creates a rotatable circle menu which can be parameterized by custom attributes.
* Handles touches and gestures to make the menu rotatable, and to make the
* menu items selectable and clickable.
*
*/
public class CircleLayout extends ViewGroup {
// Event listeners
private OnItemClickListener mOnItemClickListener = null;
private OnItemSelectedListener mOnItemSelectedListener = null;
private OnCenterClickListener mOnCenterClickListener = null;

// Background image
private Bitmap imageOriginal, imageScaled;
private Matrix matrix;

private int mTappedViewsPostition = -1;
private View mTappedView = null;
private int selected = 0;

// Child sizes
private int mMaxChildWidth = 0;
private int mMaxChildHeight = 0;
private int childWidth = 0;
private int childHeight = 0;

// Sizes of the ViewGroup
private int circleWidth, circleHeight;
private int radius = 0;

// Touch detection
private GestureDetector mGestureDetector;
// needed for detecting the inversed rotations
private boolean[] quadrantTouched;

// Settings of the ViewGroup
private boolean allowRotating = true;
private float angle = 90;
private float firstChildPos = 90;
private boolean rotateToCenter = true;
private boolean isRotating = true;

/**
* @param context
*/
public CircleLayout(Context context) {
this(context, null);
}

/**
* @param context
* @param attrs
*/
public CircleLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}

/**
* @param context
* @param attrs
* @param defStyle
*/
public CircleLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(attrs);
}

/**
* Initializes the ViewGroup and modifies it's default behavior by the passed attributes
* @param attrsthe attributes used to modify default settings
*/
protected void init(AttributeSet attrs) {
mGestureDetector = new GestureDetector(getContext(),
new MyGestureListener());
quadrantTouched = new boolean[] { false, false, false, false, false };

if (attrs != null) {
TypedArray a = getContext().obtainStyledAttributes(attrs,
R.styleable.Circle);

// The angle where the first menu item will be drawn
angle = a.getInt(R.styleable.Circle_firstChildPosition, 90);
firstChildPos = angle;

rotateToCenter = a.getBoolean(R.styleable.Circle_rotateToCenter,
true);
isRotating = a.getBoolean(R.styleable.Circle_isRotating, true);

// If the menu is not rotating then it does not have to be centered
// since it cannot be even moved
if (!isRotating) {
rotateToCenter = false;
}

if (imageOriginal == null) {
int picId = a.getResourceId(
R.styleable.Circle_circleBackground, -1);

// If a background image was set as an attribute,
// retrieve the image
if (picId != -1) {
imageOriginal = BitmapFactory.decodeResource(
getResources(), picId);
}
}

a.recycle();

// initialize the matrix only once
if (matrix == null) {
matrix = new Matrix();
} else {
// not needed, you can also post the matrix immediately to
// restore the old state
matrix.reset();
}
// Needed for the ViewGroup to be drawn
setWillNotDraw(false);
}
}

/**
* Returns the currently selected menu
* @return the view which is currently the closest to the start position
*/
public View getSelectedItem() {
return (selected >= 0) ? getChildAt(selected) : null;
}

@Override
protected void onDraw(Canvas canvas) {
// the sizes of the ViewGroup
circleHeight = getHeight();
circleWidth = getWidth();

if (imageOriginal != null) {
// Scaling the size of the background image
if (imageScaled == null) {
matrix = new Matrix();
float sx = (((radius + childWidth / 4) * 2) / (float) imageOriginal
.getWidth());
float sy = (((radius + childWidth / 4) * 2) / (float) imageOriginal
.getHeight());
matrix.postScale(sx, sy);
imageScaled = Bitmap.createBitmap(imageOriginal, 0, 0,
imageOriginal.getWidth(), imageOriginal.getHeight(),
matrix, false);
}

if (imageScaled != null) {
// Move the background to the center
int cx = (circleWidth - imageScaled.getWidth()) / 2;
int cy = (circleHeight - imageScaled.getHeight()) / 2;

Canvas g = canvas;
canvas.rotate(0, circleWidth / 2, circleHeight / 2);
g.drawBitmap(imageScaled, cx, cy, null);

}
}
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
mMaxChildWidth = 0;
mMaxChildHeight = 0;

// Measure once to find the maximum child size.
int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(
MeasureSpec.getSize(widthMeasureSpec), MeasureSpec.AT_MOST);
int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(
MeasureSpec.getSize(widthMeasureSpec), MeasureSpec.AT_MOST);

final int count = getChildCount();
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (child.getVisibility() == GONE) {
continue;
}

child.measure(childWidthMeasureSpec, childHeightMeasureSpec);

mMaxChildWidth = Math.max(mMaxChildWidth, child.getMeasuredWidth());
mMaxChildHeight = Math.max(mMaxChildHeight,
child.getMeasuredHeight());
}

// Measure again for each child to be exactly the same size.
childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(mMaxChildWidth,
MeasureSpec.EXACTLY);
childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(mMaxChildHeight,
MeasureSpec.EXACTLY);

for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (child.getVisibility() == GONE) {
continue;
}

child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}

setMeasuredDimension(resolveSize(mMaxChildWidth, widthMeasureSpec),
resolveSize(mMaxChildHeight, heightMeasureSpec));
}

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
int layoutWidth = r - l;
int layoutHeight = b - t;

// Laying out the child views
final int childCount = getChildCount();
int left, top;
radius = (layoutWidth <= layoutHeight) ? layoutWidth / 3
: layoutHeight / 3;

childWidth = (int) (radius / 1.5);
childHeight = (int) (radius / 1.5);

float angleDelay = 360 / getChildCount();

for (int i = 0; i < childCount; i++) {
final CircleImageView child = (CircleImageView) getChildAt(i);
if (child.getVisibility() == GONE) {
continue;
}

if (angle > 360) {
angle -= 360;
} else {
if (angle < 0) {
angle += 360;
}
}

child.setAngle(angle);
child.setPosition(i);

left = Math
.round((float) (((layoutWidth / 2) - childWidth / 2) + radius
* Math.cos(Math.toRadians(angle))));
top = Math
.round((float) (((layoutHeight / 2) - childHeight / 2) + radius
* Math.sin(Math.toRadians(angle))));

child.layout(left, top, left + childWidth, top + childHeight);
angle += angleDelay;
}
}

/**
* Rotate the buttons.
*
* @param degrees The degrees, the menu items should get rotated.
*/
private void rotateButtons(float degrees) {
int left, top, childCount = getChildCount();
float angleDelay = 360 / childCount;
angle += degrees;

if (angle > 360) {
angle -= 360;
} else {
if (angle < 0) {
angle += 360;
}
}

for (int i = 0; i < childCount; i++) {
if (angle > 360) {
angle -= 360;
} else {
if (angle < 0) {
angle += 360;
}
}

final CircleImageView child = (CircleImageView) getChildAt(i);
if (child.getVisibility() == GONE) {
continue;
}
left = Math
.round((float) (((circleWidth / 2) - childWidth / 2) + radius
* Math.cos(Math.toRadians(angle))));
top = Math
.round((float) (((circleHeight / 2) - childHeight / 2) + radius
* Math.sin(Math.toRadians(angle))));

child.setAngle(angle);

if (Math.abs(angle - firstChildPos) < (angleDelay / 2)
&& selected != child.getPosition()) {
selected = child.getPosition();

if (mOnItemSelectedListener != null && rotateToCenter) {
mOnItemSelectedListener.onItemSelected(child, selected,
child.getId(), child.getName());
}
}

child.layout(left, top, left + childWidth, top + childHeight);
angle += angleDelay;
}
}

/**
* @return The angle of the unit circle with the image view's center
*/
private double getAngle(double xTouch, double yTouch) {
double x = xTouch - (circleWidth / 2d);
double y = circleHeight - yTouch - (circleHeight / 2d);

switch (getQuadrant(x, y)) {
case 1:
return Math.asin(y / Math.hypot(x, y)) * 180 / Math.PI;

case 2:
case 3:
return 180 - (Math.asin(y / Math.hypot(x, y)) * 180 / Math.PI);

case 4:
return 360 + Math.asin(y / Math.hypot(x, y)) * 180 / Math.PI;

default:
// ignore, does not happen
return 0;
}
}

/**
* @return The selected quadrant.
*/
private static int getQuadrant(double x, double y) {
if (x >= 0) {
return y >= 0 ? 1 : 4;
} else {
return y >= 0 ? 2 : 3;
}
}

private double startAngle;

@Override
public boolean onTouchEvent(MotionEvent event) {
if (isEnabled()) {
if (isRotating) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:

// reset the touched quadrants
for (int i = 0; i < quadrantTouched.length; i++) {
quadrantTouched[i] = false;
}

allowRotating = false;

startAngle = getAngle(event.getX(), event.getY());
break;
case MotionEvent.ACTION_MOVE:
double currentAngle = getAngle(event.getX(), event.getY());
rotateButtons((float) (startAngle - currentAngle));
startAngle = currentAngle;
break;
case MotionEvent.ACTION_UP:
allowRotating = true;
rotateViewToCenter((CircleImageView) getChildAt(selected),
false);
break;
}
}

// set the touched quadrant to true
quadrantTouched[getQuadrant(event.getX() - (circleWidth / 2),
circleHeight - event.getY() - (circleHeight / 2))] = true;
mGestureDetector.onTouchEvent(event);
return true;
}
return false;
}

private class MyGestureListener extends SimpleOnGestureListener {
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
if (!isRotating) {
return false;
}
// get the quadrant of the start and the end of the fling
int q1 = getQuadrant(e1.getX() - (circleWidth / 2), circleHeight
- e1.getY() - (circleHeight / 2));
int q2 = getQuadrant(e2.getX() - (circleWidth / 2), circleHeight
- e2.getY() - (circleHeight / 2));

// the inversed rotations
if ((q1 == 2 && q2 == 2 && Math.abs(velocityX) < Math
.abs(velocityY))
|| (q1 == 3 && q2 == 3)
|| (q1 == 1 && q2 == 3)
|| (q1 == 4 && q2 == 4 && Math.abs(velocityX) > Math
.abs(velocityY))
|| ((q1 == 2 && q2 == 3) || (q1 == 3 && q2 == 2))
|| ((q1 == 3 && q2 == 4) || (q1 == 4 && q2 == 3))
|| (q1 == 2 && q2 == 4 && quadrantTouched[3])
|| (q1 == 4 && q2 == 2 && quadrantTouched[3])) {

CircleLayout.this.post(new FlingRunnable(-1
* (velocityX + velocityY)));
} else {
// the normal rotation
CircleLayout.this
.post(new FlingRunnable(velocityX + velocityY));
}

return true;

}

@Override
public boolean onSingleTapUp(MotionEvent e) {
mTappedViewsPostition = pointToPosition(e.getX(), e.getY());
if (mTappedViewsPostition >= 0) {
mTappedView = getChildAt(mTappedViewsPostition);
mTappedView.setPressed(true);
} else {
float centerX = circleWidth / 2;
float centerY = circleHeight / 2;

if (e.getX() < centerX + (childWidth / 2)
&& e.getX() > centerX - childWidth / 2
&& e.getY() < centerY + (childHeight / 2)
&& e.getY() > centerY - (childHeight / 2)) {
if (mOnCenterClickListener != null) {
mOnCenterClickListener.onCenterClick();
return true;
}
}
}

if (mTappedView != null) {
CircleImageView view = (CircleImageView) (mTappedView);
if (selected != mTappedViewsPostition) {
rotateViewToCenter(view, false);
if (!rotateToCenter) {
if (mOnItemSelectedListener != null) {
mOnItemSelectedListener.onItemSelected(mTappedView,
mTappedViewsPostition, mTappedView.getId(), view.getName());
}

if (mOnItemClickListener != null) {
mOnItemClickListener.onItemClick(mTappedView,
mTappedViewsPostition, mTappedView.getId(), view.getName());
}
}
} else {
rotateViewToCenter(view, false);

if (mOnItemClickListener != null) {
mOnItemClickListener.onItemClick(mTappedView,
mTappedViewsPostition, mTappedView.getId(), view.getName());
}
}
return true;
}
return super.onSingleTapUp(e);
}
}

/**
* Rotates the given view to the center of the menu.
* @param viewthe view to be rotated to the center
* @param fromRunnableif the method is called from the runnable which animates the rotation
* then it should be true, otherwise false
*/
private void rotateViewToCenter(CircleImageView view, boolean fromRunnable) {
if (rotateToCenter) {
float velocityTemp = 1;
float destAngle = (float) (firstChildPos - view.getAngle());
float startAngle = 0;
int reverser = 1;

if (destAngle < 0) {
destAngle += 360;
}

if (destAngle > 180) {
reverser = -1;
destAngle = 360 - destAngle;
}

while (startAngle < destAngle) {
startAngle += velocityTemp / 75;
velocityTemp *= 1.0666F;
}

CircleLayout.this.post(new FlingRunnable(reverser * velocityTemp,
!fromRunnable));
}
}

/**
* A {@link Runnable} for animating the menu rotation.
*/
private class FlingRunnable implements Runnable {

private float velocity;
float angleDelay;
boolean isFirstForwarding = true;

public FlingRunnable(float velocity) {
this(velocity, true);
}

public FlingRunnable(float velocity, boolean isFirst) {
this.velocity = velocity;
this.angleDelay = 360 / getChildCount();
this.isFirstForwarding = isFirst;
}

public void run() {
if (Math.abs(velocity) > 5 && allowRotating) {
if (rotateToCenter) {
if (!(Math.abs(velocity) < 200 && (Math.abs(angle
- firstChildPos)
% angleDelay < 2))) {
rotateButtons(velocity / 75);
velocity /= 1.0666F;

CircleLayout.this.post(this);
}
} else {
rotateButtons(velocity / 75);
velocity /= 1.0666F;

CircleLayout.this.post(this);
}
} else {
if (isFirstForwarding) {
isFirstForwarding = false;
CircleLayout.this.rotateViewToCenter(
(CircleImageView) getChildAt(selected), true);
}
}
}
}

private int pointToPosition(float x, float y) {

for (int i = 0; i < getChildCount(); i++) {

View item = (View) getChildAt(i);
if (item.getLeft() < x && item.getRight() > x & item.getTop() < y
&& item.getBottom() > y) {
return i;
}

}
return -1;
}

public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
this.mOnItemClickListener = onItemClickListener;
}

public interface OnItemClickListener {
void onItemClick(View view, int position, long id, String name);
}

public void setOnItemSelectedListener(
OnItemSelectedListener onItemSelectedListener) {
this.mOnItemSelectedListener = onItemSelectedListener;
}

public interface OnItemSelectedListener {
void onItemSelected(View view, int position, long id, String name);
}

public interface OnCenterClickListener {
void onCenterClick();
}

public void setOnCenterClickListener(
OnCenterClickListener onCenterClickListener) {
this.mOnCenterClickListener = onCenterClickListener;
}
}