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package com.artifex.mupdfdemo;
import java.util.LinkedList;
import java.util.NoSuchElementException;
import android.content.Context;
import android.graphics.Point;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.util.SparseArray;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.widget.Adapter;
import android.widget.AdapterView;
import android.widget.Scroller;
public class ReaderView
extends AdapterView<Adapter>
implements GestureDetector.OnGestureListener, ScaleGestureDetector.OnScaleGestureListener, Runnable {
private static final int MOVING_DIAGONALLY = 0;
private static final int MOVING_LEFT = 1;
private static final int MOVING_RIGHT = 2;
private static final int MOVING_UP = 3;
private static final int MOVING_DOWN = 4;
private static final int FLING_MARGIN = 100;
private static final int GAP = 20;
private static final float MIN_SCALE = 1.0f;
private static final float MAX_SCALE = 5.0f;
private static final float REFLOW_SCALE_FACTOR = 0.5f;
private Adapter mAdapter;
private int mCurrent; // Adapter's index for the current view
private boolean mResetLayout;
private final SparseArray<View>
mChildViews = new SparseArray<View>(3);
// Shadows the children of the adapter view
// but with more sensible indexing
private final LinkedList<View>
mViewCache = new LinkedList<View>();
private boolean mUserInteracting; // Whether the user is interacting
private boolean mScaling; // Whether the user is currently pinch zooming
private float mScale = 1.0f;
private int mXScroll; // Scroll amounts recorded from events.
private int mYScroll; // and then accounted for in onLayout
private boolean mReflow = false;
private final GestureDetector
mGestureDetector;
private final ScaleGestureDetector
mScaleGestureDetector;
private final Scroller mScroller;
private int mScrollerLastX;
private int mScrollerLastY;
private boolean mScrollDisabled;
static abstract class ViewMapper {
abstract void applyToView(View view);
}
public ReaderView(Context context) {
super(context);
mGestureDetector = new GestureDetector(this);
mScaleGestureDetector = new ScaleGestureDetector(context, this);
mScroller = new Scroller(context);
}
public ReaderView(Context context, AttributeSet attrs) {
super(context, attrs);
mGestureDetector = new GestureDetector(this);
mScaleGestureDetector = new ScaleGestureDetector(context, this);
mScroller = new Scroller(context);
}
public ReaderView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mGestureDetector = new GestureDetector(this);
mScaleGestureDetector = new ScaleGestureDetector(context, this);
mScroller = new Scroller(context);
}
public int getDisplayedViewIndex() {
return mCurrent;
}
public void setDisplayedViewIndex(int i) {
if (0 <= i && i < mAdapter.getCount()) {
onMoveOffChild(mCurrent);
mCurrent = i;
onMoveToChild(i);
mResetLayout = true;
requestLayout();
}
}
public void moveToNext() {
View v = mChildViews.get(mCurrent+1);
if (v != null)
slideViewOntoScreen(v);
}
public void moveToPrevious() {
View v = mChildViews.get(mCurrent-1);
if (v != null)
slideViewOntoScreen(v);
}
// When advancing down the page, we want to advance by about
// 90% of a screenful. But we'd be happy to advance by between
// 80% and 95% if it means we hit the bottom in a whole number
// of steps.
private int smartAdvanceAmount(int screenHeight, int max) {
int advance = (int)(screenHeight * 0.9 + 0.5);
int leftOver = max % advance;
int steps = max / advance;
if (leftOver == 0) {
// We'll make it exactly. No adjustment
} else if ((float)leftOver / steps <= screenHeight * 0.05) {
// We can adjust up by less than 5% to make it exact.
advance += (int)((float)leftOver/steps + 0.5);
} else {
int overshoot = advance - leftOver;
if ((float)overshoot / steps <= screenHeight * 0.1) {
// We can adjust down by less than 10% to make it exact.
advance -= (int)((float)overshoot/steps + 0.5);
}
}
if (advance > max)
advance = max;
return advance;
}
public void smartMoveForwards() {
View v = mChildViews.get(mCurrent);
if (v == null)
return;
// The following code works in terms of where the screen is on the views;
// so for example, if the currentView is at (-100,-100), the visible
// region would be at (100,100). If the previous page was (2000, 3000) in
// size, the visible region of the previous page might be (2100 + GAP, 100)
// (i.e. off the previous page). This is different to the way the rest of
// the code in this file is written, but it's easier for me to think about.
// At some point we may refactor this to fit better with the rest of the
// code.
// screenWidth/Height are the actual width/height of the screen. e.g. 480/800
int screenWidth = getWidth();
int screenHeight = getHeight();
// We might be mid scroll; we want to calculate where we scroll to based on
// where this scroll would end, not where we are now (to allow for people
// bashing 'forwards' very fast.
int remainingX = mScroller.getFinalX() - mScroller.getCurrX();
int remainingY = mScroller.getFinalY() - mScroller.getCurrY();
// right/bottom is in terms of pixels within the scaled document; e.g. 1000
int top = -(v.getTop() + mYScroll + remainingY);
int right = screenWidth -(v.getLeft() + mXScroll + remainingX);
int bottom = screenHeight+top;
// docWidth/Height are the width/height of the scaled document e.g. 2000x3000
int docWidth = v.getMeasuredWidth();
int docHeight = v.getMeasuredHeight();
int xOffset, yOffset;
if (bottom >= docHeight) {
// We are flush with the bottom. Advance to next column.
if (right + screenWidth > docWidth) {
// No room for another column - go to next page
View nv = mChildViews.get(mCurrent+1);
if (nv == null) // No page to advance to
return;
int nextTop = -(nv.getTop() + mYScroll + remainingY);
int nextLeft = -(nv.getLeft() + mXScroll + remainingX);
int nextDocWidth = nv.getMeasuredWidth();
int nextDocHeight = nv.getMeasuredHeight();
// Allow for the next page maybe being shorter than the screen is high
yOffset = (nextDocHeight < screenHeight ? ((nextDocHeight - screenHeight)>>1) : 0);
if (nextDocWidth < screenWidth) {
// Next page is too narrow to fill the screen. Scroll to the top, centred.
xOffset = (nextDocWidth - screenWidth)>>1;
} else {
// Reset X back to the left hand column
xOffset = right % screenWidth;
// Adjust in case the previous page is less wide
if (xOffset + screenWidth > nextDocWidth)
xOffset = nextDocWidth - screenWidth;
}
xOffset -= nextLeft;
yOffset -= nextTop;
} else {
// Move to top of next column
xOffset = screenWidth;
yOffset = screenHeight - bottom;
}
} else {
// Advance by 90% of the screen height downwards (in case lines are partially cut off)
xOffset = 0;
yOffset = smartAdvanceAmount(screenHeight, docHeight - bottom);
}
mScrollerLastX = mScrollerLastY = 0;
mScroller.startScroll(0, 0, remainingX - xOffset, remainingY - yOffset, 400);
post(this);
}
public void smartMoveBackwards() {
View v = mChildViews.get(mCurrent);
if (v == null)
return;
// The following code works in terms of where the screen is on the views;
// so for example, if the currentView is at (-100,-100), the visible
// region would be at (100,100). If the previous page was (2000, 3000) in
// size, the visible region of the previous page might be (2100 + GAP, 100)
// (i.e. off the previous page). This is different to the way the rest of
// the code in this file is written, but it's easier for me to think about.
// At some point we may refactor this to fit better with the rest of the
// code.
// screenWidth/Height are the actual width/height of the screen. e.g. 480/800
int screenWidth = getWidth();
int screenHeight = getHeight();
// We might be mid scroll; we want to calculate where we scroll to based on
// where this scroll would end, not where we are now (to allow for people
// bashing 'forwards' very fast.
int remainingX = mScroller.getFinalX() - mScroller.getCurrX();
int remainingY = mScroller.getFinalY() - mScroller.getCurrY();
// left/top is in terms of pixels within the scaled document; e.g. 1000
int left = -(v.getLeft() + mXScroll + remainingX);
int top = -(v.getTop() + mYScroll + remainingY);
// docWidth/Height are the width/height of the scaled document e.g. 2000x3000
int docHeight = v.getMeasuredHeight();
int xOffset, yOffset;
if (top <= 0) {
// We are flush with the top. Step back to previous column.
if (left < screenWidth) {
/* No room for previous column - go to previous page */
View pv = mChildViews.get(mCurrent-1);
if (pv == null) /* No page to advance to */
return;
int prevDocWidth = pv.getMeasuredWidth();
int prevDocHeight = pv.getMeasuredHeight();
// Allow for the next page maybe being shorter than the screen is high
yOffset = (prevDocHeight < screenHeight ? ((prevDocHeight - screenHeight)>>1) : 0);
int prevLeft = -(pv.getLeft() + mXScroll);
int prevTop = -(pv.getTop() + mYScroll);
if (prevDocWidth < screenWidth) {
// Previous page is too narrow to fill the screen. Scroll to the bottom, centred.
xOffset = (prevDocWidth - screenWidth)>>1;
} else {
// Reset X back to the right hand column
xOffset = (left > 0 ? left % screenWidth : 0);
if (xOffset + screenWidth > prevDocWidth)
xOffset = prevDocWidth - screenWidth;
while (xOffset + screenWidth*2 < prevDocWidth)
xOffset += screenWidth;
}
xOffset -= prevLeft;
yOffset -= prevTop-prevDocHeight+screenHeight;
} else {
// Move to bottom of previous column
xOffset = -screenWidth;
yOffset = docHeight - screenHeight + top;
}
} else {
// Retreat by 90% of the screen height downwards (in case lines are partially cut off)
xOffset = 0;
yOffset = -smartAdvanceAmount(screenHeight, top);
}
mScrollerLastX = mScrollerLastY = 0;
mScroller.startScroll(0, 0, remainingX - xOffset, remainingY - yOffset, 400);
post(this);
}
public void resetupChildren() {
for (int i = 0; i < mChildViews.size(); i++)
onChildSetup(mChildViews.keyAt(i), mChildViews.valueAt(i));
}
public void applyToChildren(ViewMapper mapper) {
for (int i = 0; i < mChildViews.size(); i++)
mapper.applyToView(mChildViews.valueAt(i));
}
public void refresh(boolean reflow) {
mReflow = reflow;
mScale = 1.0f;
mXScroll = mYScroll = 0;
int numChildren = mChildViews.size();
for (int i = 0; i < numChildren; i++) {
View v = mChildViews.valueAt(i);
onNotInUse(v);
removeViewInLayout(v);
}
mChildViews.clear();
mViewCache.clear();
requestLayout();
}
protected void onChildSetup(int i, View v) {}
protected void onMoveToChild(int i) {}
protected void onMoveOffChild(int i) {}
protected void onSettle(View v) {};
protected void onUnsettle(View v) {};
protected void onNotInUse(View v) {};
protected void onScaleChild(View v, Float scale) {};
public View getView(int i) {
return mChildViews.get(i);
}
public View getDisplayedView() {
return mChildViews.get(mCurrent);
}
public void run() {
if (!mScroller.isFinished()) {
mScroller.computeScrollOffset();
int x = mScroller.getCurrX();
int y = mScroller.getCurrY();
mXScroll += x - mScrollerLastX;
mYScroll += y - mScrollerLastY;
mScrollerLastX = x;
mScrollerLastY = y;
requestLayout();
post(this);
}
else if (!mUserInteracting) {
// End of an inertial scroll and the user is not interacting.
// The layout is stable
View v = mChildViews.get(mCurrent);
if (v != null)
postSettle(v);
}
}
public boolean onDown(MotionEvent arg0) {
mScroller.forceFinished(true);
return true;
}
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
if (mScrollDisabled)
return true;
View v = mChildViews.get(mCurrent);
if (v != null) {
Rect bounds = getScrollBounds(v);
switch(directionOfTravel(velocityX, velocityY)) {
case MOVING_LEFT:
if (bounds.left >= 0) {
// Fling off to the left bring next view onto screen
View vl = mChildViews.get(mCurrent+1);
if (vl != null) {
slideViewOntoScreen(vl);
return true;
}
}
break;
case MOVING_RIGHT:
if (bounds.right <= 0) {
// Fling off to the right bring previous view onto screen
View vr = mChildViews.get(mCurrent-1);
if (vr != null) {
slideViewOntoScreen(vr);
return true;
}
}
break;
}
mScrollerLastX = mScrollerLastY = 0;
// If the page has been dragged out of bounds then we want to spring back
// nicely. fling jumps back into bounds instantly, so we don't want to use
// fling in that case. On the other hand, we don't want to forgo a fling
// just because of a slightly off-angle drag taking us out of bounds other
// than in the direction of the drag, so we test for out of bounds only
// in the direction of travel.
//
// Also don't fling if out of bounds in any direction by more than fling
// margin
Rect expandedBounds = new Rect(bounds);
expandedBounds.inset(-FLING_MARGIN, -FLING_MARGIN);
if(withinBoundsInDirectionOfTravel(bounds, velocityX, velocityY)
&& expandedBounds.contains(0, 0)) {
mScroller.fling(0, 0, (int)velocityX, (int)velocityY, bounds.left, bounds.right, bounds.top, bounds.bottom);
post(this);
}
}
return true;
}
public void onLongPress(MotionEvent e) {
}
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
float distanceY) {
if (!mScrollDisabled) {
mXScroll -= distanceX;
mYScroll -= distanceY;
requestLayout();
}
return true;
}
public void onShowPress(MotionEvent e) {
}
public boolean onSingleTapUp(MotionEvent e) {
return false;
}
public boolean onScale(ScaleGestureDetector detector) {
float previousScale = mScale;
float scale_factor = mReflow ? REFLOW_SCALE_FACTOR : 1.0f;
float min_scale = MIN_SCALE * scale_factor;
float max_scale = MAX_SCALE * scale_factor;
mScale = Math.min(Math.max(mScale * detector.getScaleFactor(), min_scale), max_scale);
if (mReflow) {
applyToChildren(new ViewMapper() {
@Override
void applyToView(View view) {
onScaleChild(view, mScale);
}
});
} else {
float factor = mScale/previousScale;
View v = mChildViews.get(mCurrent);
if (v != null) {
// Work out the focus point relative to the view top left
int viewFocusX = (int)detector.getFocusX() - (v.getLeft() + mXScroll);
int viewFocusY = (int)detector.getFocusY() - (v.getTop() + mYScroll);
// Scroll to maintain the focus point
mXScroll += viewFocusX - viewFocusX * factor;
mYScroll += viewFocusY - viewFocusY * factor;
requestLayout();
}
}
return true;
}
public boolean onScaleBegin(ScaleGestureDetector detector) {
mScaling = true;
// Ignore any scroll amounts yet to be accounted for: the
// screen is not showing the effect of them, so they can
// only confuse the user
mXScroll = mYScroll = 0;
// Avoid jump at end of scaling by disabling scrolling
// until the next start of gesture
mScrollDisabled = true;
return true;
}
public void onScaleEnd(ScaleGestureDetector detector) {
mScaling = false;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
mScaleGestureDetector.onTouchEvent(event);
if (!mScaling)
mGestureDetector.onTouchEvent(event);
if ((event.getAction() & event.ACTION_MASK) == MotionEvent.ACTION_DOWN) {
mUserInteracting = true;
}
if ((event.getAction() & event.ACTION_MASK) == MotionEvent.ACTION_UP) {
mScrollDisabled = false;
mUserInteracting = false;
View v = mChildViews.get(mCurrent);
if (v != null) {
if (mScroller.isFinished()) {
// If, at the end of user interaction, there is no
// current inertial scroll in operation then animate
// the view onto screen if necessary
slideViewOntoScreen(v);
}
if (mScroller.isFinished()) {
// If still there is no inertial scroll in operation
// then the layout is stable
postSettle(v);
}
}
}
requestLayout();
return true;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int n = getChildCount();
for (int i = 0; i < n; i++)
measureView(getChildAt(i));
}
@Override
protected void onLayout(boolean changed, int left, int top, int right,
int bottom) {
super.onLayout(changed, left, top, right, bottom);
View cv = mChildViews.get(mCurrent);
Point cvOffset;
if (!mResetLayout) {
// Move to next or previous if current is sufficiently off center
if (cv != null) {
cvOffset = subScreenSizeOffset(cv);
// cv.getRight() may be out of date with the current scale
// so add left to the measured width for the correct position
if (cv.getLeft() + cv.getMeasuredWidth() + cvOffset.x + GAP/2 + mXScroll < getWidth()/2 && mCurrent + 1 < mAdapter.getCount()) {
postUnsettle(cv);
// post to invoke test for end of animation
// where we must set hq area for the new current view
post(this);
onMoveOffChild(mCurrent);
mCurrent++;
onMoveToChild(mCurrent);
}
if (cv.getLeft() - cvOffset.x - GAP/2 + mXScroll >= getWidth()/2 && mCurrent > 0) {
postUnsettle(cv);
// post to invoke test for end of animation
// where we must set hq area for the new current view
post(this);
onMoveOffChild(mCurrent);
mCurrent--;
onMoveToChild(mCurrent);
}
}
// Remove not needed children and hold them for reuse
int numChildren = mChildViews.size();
int childIndices[] = new int[numChildren];
for (int i = 0; i < numChildren; i++)
childIndices[i] = mChildViews.keyAt(i);
for (int i = 0; i < numChildren; i++) {
int ai = childIndices[i];
if (ai < mCurrent - 1 || ai > mCurrent + 1) {
View v = mChildViews.get(ai);
onNotInUse(v);
mViewCache.add(v);
removeViewInLayout(v);
mChildViews.remove(ai);
}
}
} else {
mResetLayout = false;
mXScroll = mYScroll = 0;
// Remove all children and hold them for reuse
int numChildren = mChildViews.size();
for (int i = 0; i < numChildren; i++) {
View v = mChildViews.valueAt(i);
onNotInUse(v);
mViewCache.add(v);
removeViewInLayout(v);
}
mChildViews.clear();
// post to ensure generation of hq area
post(this);
}
// Ensure current view is present
int cvLeft, cvRight, cvTop, cvBottom;
boolean notPresent = (mChildViews.get(mCurrent) == null);
cv = getOrCreateChild(mCurrent);
// When the view is sub-screen-size in either dimension we
// offset it to center within the screen area, and to keep
// the views spaced out
cvOffset = subScreenSizeOffset(cv);
if (notPresent) {
//Main item not already present. Just place it top left
cvLeft = cvOffset.x;
cvTop = cvOffset.y;
} else {
// Main item already present. Adjust by scroll offsets
cvLeft = cv.getLeft() + mXScroll;
cvTop = cv.getTop() + mYScroll;
}
// Scroll values have been accounted for
mXScroll = mYScroll = 0;
cvRight = cvLeft + cv.getMeasuredWidth();
cvBottom = cvTop + cv.getMeasuredHeight();
if (!mUserInteracting && mScroller.isFinished()) {
Point corr = getCorrection(getScrollBounds(cvLeft, cvTop, cvRight, cvBottom));
cvRight += corr.x;
cvLeft += corr.x;
cvTop += corr.y;
cvBottom += corr.y;
} else if (cv.getMeasuredHeight() <= getHeight()) {
// When the current view is as small as the screen in height, clamp
// it vertically
Point corr = getCorrection(getScrollBounds(cvLeft, cvTop, cvRight, cvBottom));
cvTop += corr.y;
cvBottom += corr.y;
}
cv.layout(cvLeft, cvTop, cvRight, cvBottom);
if (mCurrent > 0) {
View lv = getOrCreateChild(mCurrent - 1);
Point leftOffset = subScreenSizeOffset(lv);
int gap = leftOffset.x + GAP + cvOffset.x;
lv.layout(cvLeft - lv.getMeasuredWidth() - gap,
(cvBottom + cvTop - lv.getMeasuredHeight())/2,
cvLeft - gap,
(cvBottom + cvTop + lv.getMeasuredHeight())/2);
}
if (mCurrent + 1 < mAdapter.getCount()) {
View rv = getOrCreateChild(mCurrent + 1);
Point rightOffset = subScreenSizeOffset(rv);
int gap = cvOffset.x + GAP + rightOffset.x;
rv.layout(cvRight + gap,
(cvBottom + cvTop - rv.getMeasuredHeight())/2,
cvRight + rv.getMeasuredWidth() + gap,
(cvBottom + cvTop + rv.getMeasuredHeight())/2);
}
invalidate();
}
@Override
public Adapter getAdapter() {
return mAdapter;
}
@Override
public View getSelectedView() {
throw new UnsupportedOperationException(getContext().getString(R.string.not_supported));
}
@Override
public void setAdapter(Adapter adapter) {
mAdapter = adapter;
mChildViews.clear();
removeAllViewsInLayout();
requestLayout();
}
@Override
public void setSelection(int arg0) {
throw new UnsupportedOperationException(getContext().getString(R.string.not_supported));
}
private View getCached() {
if (mViewCache.size() == 0)
return null;
else
return mViewCache.removeFirst();
}
private View getOrCreateChild(int i) {
View v = mChildViews.get(i);
if (v == null) {
v = mAdapter.getView(i, getCached(), this);
addAndMeasureChild(i, v);
onChildSetup(i, v);
onScaleChild(v, mScale);
}
return v;
}
private void addAndMeasureChild(int i, View v) {
LayoutParams params = v.getLayoutParams();
if (params == null) {
params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
}
addViewInLayout(v, 0, params, true);
mChildViews.append(i, v); // Record the view against it's adapter index
measureView(v);
}
private void measureView(View v) {
// See what size the view wants to be
v.measure(View.MeasureSpec.UNSPECIFIED, View.MeasureSpec.UNSPECIFIED);
if (!mReflow) {
// Work out a scale that will fit it to this view
float scale = Math.min((float)getWidth()/(float)v.getMeasuredWidth(),
(float)getHeight()/(float)v.getMeasuredHeight());
// Use the fitting values scaled by our current scale factor
v.measure(View.MeasureSpec.EXACTLY | (int)(v.getMeasuredWidth()*scale*mScale),
View.MeasureSpec.EXACTLY | (int)(v.getMeasuredHeight()*scale*mScale));
} else {
v.measure(View.MeasureSpec.EXACTLY | (int)(v.getMeasuredWidth()),
View.MeasureSpec.EXACTLY | (int)(v.getMeasuredHeight()));
}
}
private Rect getScrollBounds(int left, int top, int right, int bottom) {
int xmin = getWidth() - right;
int xmax = -left;
int ymin = getHeight() - bottom;
int ymax = -top;
// In either dimension, if view smaller than screen then
// constrain it to be central
if (xmin > xmax) xmin = xmax = (xmin + xmax)/2;
if (ymin > ymax) ymin = ymax = (ymin + ymax)/2;
return new Rect(xmin, ymin, xmax, ymax);
}
private Rect getScrollBounds(View v) {
// There can be scroll amounts not yet accounted for in
// onLayout, so add mXScroll and mYScroll to the current
// positions when calculating the bounds.
return getScrollBounds(v.getLeft() + mXScroll,
v.getTop() + mYScroll,
v.getLeft() + v.getMeasuredWidth() + mXScroll,
v.getTop() + v.getMeasuredHeight() + mYScroll);
}
private Point getCorrection(Rect bounds) {
return new Point(Math.min(Math.max(0,bounds.left),bounds.right),
Math.min(Math.max(0,bounds.top),bounds.bottom));
}
private void postSettle(final View v) {
// onSettle and onUnsettle are posted so that the calls
// wont be executed until after the system has performed
// layout.
post (new Runnable() {
public void run () {
onSettle(v);
}
});
}
private void postUnsettle(final View v) {
post (new Runnable() {
public void run () {
onUnsettle(v);
}
});
}
private void slideViewOntoScreen(View v) {
Point corr = getCorrection(getScrollBounds(v));
if (corr.x != 0 || corr.y != 0) {
mScrollerLastX = mScrollerLastY = 0;
mScroller.startScroll(0, 0, corr.x, corr.y, 400);
post(this);
}
}
private Point subScreenSizeOffset(View v) {
return new Point(Math.max((getWidth() - v.getMeasuredWidth())/2, 0),
Math.max((getHeight() - v.getMeasuredHeight())/2, 0));
}
private static int directionOfTravel(float vx, float vy) {
if (Math.abs(vx) > 2 * Math.abs(vy))
return (vx > 0) ? MOVING_RIGHT : MOVING_LEFT;
else if (Math.abs(vy) > 2 * Math.abs(vx))
return (vy > 0) ? MOVING_DOWN : MOVING_UP;
else
return MOVING_DIAGONALLY;
}
private static boolean withinBoundsInDirectionOfTravel(Rect bounds, float vx, float vy) {
switch (directionOfTravel(vx, vy)) {
case MOVING_DIAGONALLY: return bounds.contains(0, 0);
case MOVING_LEFT: return bounds.left <= 0;
case MOVING_RIGHT: return bounds.right >= 0;
case MOVING_UP: return bounds.top <= 0;
case MOVING_DOWN: return bounds.bottom >= 0;
default: throw new NoSuchElementException();
}
}
}
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