Java tutorial
/* * Copyright (C) 2008-2009 Google Inc. * * 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. */ package android.inputmethodservice; import android.annotation.UnsupportedAppUsage; import android.content.Context; import android.content.res.TypedArray; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Paint.Align; import android.graphics.PorterDuff; import android.graphics.Rect; import android.graphics.Typeface; import android.graphics.drawable.Drawable; import android.inputmethodservice.Keyboard.Key; import android.media.AudioManager; import android.os.Handler; import android.os.Message; import android.util.AttributeSet; import android.util.TypedValue; import android.view.GestureDetector; import android.view.Gravity; import android.view.LayoutInflater; import android.view.MotionEvent; import android.view.View; import android.view.ViewConfiguration; import android.view.ViewGroup.LayoutParams; import android.view.accessibility.AccessibilityEvent; import android.view.accessibility.AccessibilityManager; import android.widget.PopupWindow; import android.widget.TextView; import com.android.internal.R; import java.util.Arrays; import java.util.HashMap; import java.util.List; import java.util.Map; /** * A view that renders a virtual {@link Keyboard}. It handles rendering of keys and * detecting key presses and touch movements. * * @attr ref android.R.styleable#KeyboardView_keyBackground * @attr ref android.R.styleable#KeyboardView_keyPreviewLayout * @attr ref android.R.styleable#KeyboardView_keyPreviewOffset * @attr ref android.R.styleable#KeyboardView_keyPreviewHeight * @attr ref android.R.styleable#KeyboardView_labelTextSize * @attr ref android.R.styleable#KeyboardView_keyTextSize * @attr ref android.R.styleable#KeyboardView_keyTextColor * @attr ref android.R.styleable#KeyboardView_verticalCorrection * @attr ref android.R.styleable#KeyboardView_popupLayout */ public class KeyboardView extends View implements View.OnClickListener { /** * Listener for virtual keyboard events. */ public interface OnKeyboardActionListener { /** * Called when the user presses a key. This is sent before the {@link #onKey} is called. * For keys that repeat, this is only called once. * @param primaryCode the unicode of the key being pressed. If the touch is not on a valid * key, the value will be zero. */ void onPress(int primaryCode); /** * Called when the user releases a key. This is sent after the {@link #onKey} is called. * For keys that repeat, this is only called once. * @param primaryCode the code of the key that was released */ void onRelease(int primaryCode); /** * Send a key press to the listener. * @param primaryCode this is the key that was pressed * @param keyCodes the codes for all the possible alternative keys * with the primary code being the first. If the primary key code is * a single character such as an alphabet or number or symbol, the alternatives * will include other characters that may be on the same key or adjacent keys. * These codes are useful to correct for accidental presses of a key adjacent to * the intended key. */ void onKey(int primaryCode, int[] keyCodes); /** * Sends a sequence of characters to the listener. * @param text the sequence of characters to be displayed. */ void onText(CharSequence text); /** * Called when the user quickly moves the finger from right to left. */ void swipeLeft(); /** * Called when the user quickly moves the finger from left to right. */ void swipeRight(); /** * Called when the user quickly moves the finger from up to down. */ void swipeDown(); /** * Called when the user quickly moves the finger from down to up. */ void swipeUp(); } private static final boolean DEBUG = false; private static final int NOT_A_KEY = -1; private static final int[] KEY_DELETE = { Keyboard.KEYCODE_DELETE }; private static final int[] LONG_PRESSABLE_STATE_SET = { R.attr.state_long_pressable }; private Keyboard mKeyboard; private int mCurrentKeyIndex = NOT_A_KEY; @UnsupportedAppUsage private int mLabelTextSize; private int mKeyTextSize; private int mKeyTextColor; private float mShadowRadius; private int mShadowColor; private float mBackgroundDimAmount; @UnsupportedAppUsage private TextView mPreviewText; private PopupWindow mPreviewPopup; private int mPreviewTextSizeLarge; private int mPreviewOffset; private int mPreviewHeight; // Working variable private final int[] mCoordinates = new int[2]; private PopupWindow mPopupKeyboard; private View mMiniKeyboardContainer; private KeyboardView mMiniKeyboard; private boolean mMiniKeyboardOnScreen; private View mPopupParent; private int mMiniKeyboardOffsetX; private int mMiniKeyboardOffsetY; private Map<Key, View> mMiniKeyboardCache; private Key[] mKeys; /** Listener for {@link OnKeyboardActionListener}. */ private OnKeyboardActionListener mKeyboardActionListener; private static final int MSG_SHOW_PREVIEW = 1; private static final int MSG_REMOVE_PREVIEW = 2; private static final int MSG_REPEAT = 3; private static final int MSG_LONGPRESS = 4; private static final int DELAY_BEFORE_PREVIEW = 0; private static final int DELAY_AFTER_PREVIEW = 70; private static final int DEBOUNCE_TIME = 70; private int mVerticalCorrection; private int mProximityThreshold; private boolean mPreviewCentered = false; private boolean mShowPreview = true; private boolean mShowTouchPoints = true; private int mPopupPreviewX; private int mPopupPreviewY; private int mLastX; private int mLastY; private int mStartX; private int mStartY; private boolean mProximityCorrectOn; private Paint mPaint; private Rect mPadding; private long mDownTime; private long mLastMoveTime; private int mLastKey; private int mLastCodeX; private int mLastCodeY; private int mCurrentKey = NOT_A_KEY; private int mDownKey = NOT_A_KEY; private long mLastKeyTime; private long mCurrentKeyTime; private int[] mKeyIndices = new int[12]; private GestureDetector mGestureDetector; private int mPopupX; private int mPopupY; private int mRepeatKeyIndex = NOT_A_KEY; private int mPopupLayout; private boolean mAbortKey; private Key mInvalidatedKey; private Rect mClipRegion = new Rect(0, 0, 0, 0); private boolean mPossiblePoly; private SwipeTracker mSwipeTracker = new SwipeTracker(); private int mSwipeThreshold; private boolean mDisambiguateSwipe; // Variables for dealing with multiple pointers private int mOldPointerCount = 1; private float mOldPointerX; private float mOldPointerY; @UnsupportedAppUsage private Drawable mKeyBackground; private static final int REPEAT_INTERVAL = 50; // ~20 keys per second private static final int REPEAT_START_DELAY = 400; private static final int LONGPRESS_TIMEOUT = ViewConfiguration.getLongPressTimeout(); private static int MAX_NEARBY_KEYS = 12; private int[] mDistances = new int[MAX_NEARBY_KEYS]; // For multi-tap private int mLastSentIndex; private int mTapCount; private long mLastTapTime; private boolean mInMultiTap; private static final int MULTITAP_INTERVAL = 800; // milliseconds private StringBuilder mPreviewLabel = new StringBuilder(1); /** Whether the keyboard bitmap needs to be redrawn before it's blitted. **/ private boolean mDrawPending; /** The dirty region in the keyboard bitmap */ private Rect mDirtyRect = new Rect(); /** The keyboard bitmap for faster updates */ private Bitmap mBuffer; /** Notes if the keyboard just changed, so that we could possibly reallocate the mBuffer. */ private boolean mKeyboardChanged; /** The canvas for the above mutable keyboard bitmap */ private Canvas mCanvas; /** The accessibility manager for accessibility support */ private AccessibilityManager mAccessibilityManager; /** The audio manager for accessibility support */ private AudioManager mAudioManager; /** Whether the requirement of a headset to hear passwords if accessibility is enabled is announced. */ private boolean mHeadsetRequiredToHearPasswordsAnnounced; Handler mHandler; public KeyboardView(Context context, AttributeSet attrs) { this(context, attrs, com.android.internal.R.attr.keyboardViewStyle); } public KeyboardView(Context context, AttributeSet attrs, int defStyleAttr) { this(context, attrs, defStyleAttr, 0); } public KeyboardView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { super(context, attrs, defStyleAttr, defStyleRes); TypedArray a = context.obtainStyledAttributes(attrs, android.R.styleable.KeyboardView, defStyleAttr, defStyleRes); LayoutInflater inflate = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); int previewLayout = 0; int keyTextSize = 0; int n = a.getIndexCount(); for (int i = 0; i < n; i++) { int attr = a.getIndex(i); switch (attr) { case com.android.internal.R.styleable.KeyboardView_keyBackground: mKeyBackground = a.getDrawable(attr); break; case com.android.internal.R.styleable.KeyboardView_verticalCorrection: mVerticalCorrection = a.getDimensionPixelOffset(attr, 0); break; case com.android.internal.R.styleable.KeyboardView_keyPreviewLayout: previewLayout = a.getResourceId(attr, 0); break; case com.android.internal.R.styleable.KeyboardView_keyPreviewOffset: mPreviewOffset = a.getDimensionPixelOffset(attr, 0); break; case com.android.internal.R.styleable.KeyboardView_keyPreviewHeight: mPreviewHeight = a.getDimensionPixelSize(attr, 80); break; case com.android.internal.R.styleable.KeyboardView_keyTextSize: mKeyTextSize = a.getDimensionPixelSize(attr, 18); break; case com.android.internal.R.styleable.KeyboardView_keyTextColor: mKeyTextColor = a.getColor(attr, 0xFF000000); break; case com.android.internal.R.styleable.KeyboardView_labelTextSize: mLabelTextSize = a.getDimensionPixelSize(attr, 14); break; case com.android.internal.R.styleable.KeyboardView_popupLayout: mPopupLayout = a.getResourceId(attr, 0); break; case com.android.internal.R.styleable.KeyboardView_shadowColor: mShadowColor = a.getColor(attr, 0); break; case com.android.internal.R.styleable.KeyboardView_shadowRadius: mShadowRadius = a.getFloat(attr, 0f); break; } } a = mContext.obtainStyledAttributes(com.android.internal.R.styleable.Theme); mBackgroundDimAmount = a.getFloat(android.R.styleable.Theme_backgroundDimAmount, 0.5f); mPreviewPopup = new PopupWindow(context); if (previewLayout != 0) { mPreviewText = (TextView) inflate.inflate(previewLayout, null); mPreviewTextSizeLarge = (int) mPreviewText.getTextSize(); mPreviewPopup.setContentView(mPreviewText); mPreviewPopup.setBackgroundDrawable(null); } else { mShowPreview = false; } mPreviewPopup.setTouchable(false); mPopupKeyboard = new PopupWindow(context); mPopupKeyboard.setBackgroundDrawable(null); //mPopupKeyboard.setClippingEnabled(false); mPopupParent = this; //mPredicting = true; mPaint = new Paint(); mPaint.setAntiAlias(true); mPaint.setTextSize(keyTextSize); mPaint.setTextAlign(Align.CENTER); mPaint.setAlpha(255); mPadding = new Rect(0, 0, 0, 0); mMiniKeyboardCache = new HashMap<Key, View>(); mKeyBackground.getPadding(mPadding); mSwipeThreshold = (int) (500 * getResources().getDisplayMetrics().density); mDisambiguateSwipe = getResources().getBoolean(com.android.internal.R.bool.config_swipeDisambiguation); mAccessibilityManager = AccessibilityManager.getInstance(context); mAudioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE); resetMultiTap(); } @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); initGestureDetector(); if (mHandler == null) { mHandler = new Handler() { @Override public void handleMessage(Message msg) { switch (msg.what) { case MSG_SHOW_PREVIEW: showKey(msg.arg1); break; case MSG_REMOVE_PREVIEW: mPreviewText.setVisibility(INVISIBLE); break; case MSG_REPEAT: if (repeatKey()) { Message repeat = Message.obtain(this, MSG_REPEAT); sendMessageDelayed(repeat, REPEAT_INTERVAL); } break; case MSG_LONGPRESS: openPopupIfRequired((MotionEvent) msg.obj); break; } } }; } } private void initGestureDetector() { if (mGestureDetector == null) { mGestureDetector = new GestureDetector(getContext(), new GestureDetector.SimpleOnGestureListener() { @Override public boolean onFling(MotionEvent me1, MotionEvent me2, float velocityX, float velocityY) { if (mPossiblePoly) return false; final float absX = Math.abs(velocityX); final float absY = Math.abs(velocityY); float deltaX = me2.getX() - me1.getX(); float deltaY = me2.getY() - me1.getY(); int travelX = getWidth() / 2; // Half the keyboard width int travelY = getHeight() / 2; // Half the keyboard height mSwipeTracker.computeCurrentVelocity(1000); final float endingVelocityX = mSwipeTracker.getXVelocity(); final float endingVelocityY = mSwipeTracker.getYVelocity(); boolean sendDownKey = false; if (velocityX > mSwipeThreshold && absY < absX && deltaX > travelX) { if (mDisambiguateSwipe && endingVelocityX < velocityX / 4) { sendDownKey = true; } else { swipeRight(); return true; } } else if (velocityX < -mSwipeThreshold && absY < absX && deltaX < -travelX) { if (mDisambiguateSwipe && endingVelocityX > velocityX / 4) { sendDownKey = true; } else { swipeLeft(); return true; } } else if (velocityY < -mSwipeThreshold && absX < absY && deltaY < -travelY) { if (mDisambiguateSwipe && endingVelocityY > velocityY / 4) { sendDownKey = true; } else { swipeUp(); return true; } } else if (velocityY > mSwipeThreshold && absX < absY / 2 && deltaY > travelY) { if (mDisambiguateSwipe && endingVelocityY < velocityY / 4) { sendDownKey = true; } else { swipeDown(); return true; } } if (sendDownKey) { detectAndSendKey(mDownKey, mStartX, mStartY, me1.getEventTime()); } return false; } }); mGestureDetector.setIsLongpressEnabled(false); } } public void setOnKeyboardActionListener(OnKeyboardActionListener listener) { mKeyboardActionListener = listener; } /** * Returns the {@link OnKeyboardActionListener} object. * @return the listener attached to this keyboard */ protected OnKeyboardActionListener getOnKeyboardActionListener() { return mKeyboardActionListener; } /** * Attaches a keyboard to this view. The keyboard can be switched at any time and the * view will re-layout itself to accommodate the keyboard. * @see Keyboard * @see #getKeyboard() * @param keyboard the keyboard to display in this view */ public void setKeyboard(Keyboard keyboard) { if (mKeyboard != null) { showPreview(NOT_A_KEY); } // Remove any pending messages removeMessages(); mKeyboard = keyboard; List<Key> keys = mKeyboard.getKeys(); mKeys = keys.toArray(new Key[keys.size()]); requestLayout(); // Hint to reallocate the buffer if the size changed mKeyboardChanged = true; invalidateAllKeys(); computeProximityThreshold(keyboard); mMiniKeyboardCache.clear(); // Not really necessary to do every time, but will free up views // Switching to a different keyboard should abort any pending keys so that the key up // doesn't get delivered to the old or new keyboard mAbortKey = true; // Until the next ACTION_DOWN } /** * Returns the current keyboard being displayed by this view. * @return the currently attached keyboard * @see #setKeyboard(Keyboard) */ public Keyboard getKeyboard() { return mKeyboard; } /** * Sets the state of the shift key of the keyboard, if any. * @param shifted whether or not to enable the state of the shift key * @return true if the shift key state changed, false if there was no change * @see KeyboardView#isShifted() */ public boolean setShifted(boolean shifted) { if (mKeyboard != null) { if (mKeyboard.setShifted(shifted)) { // The whole keyboard probably needs to be redrawn invalidateAllKeys(); return true; } } return false; } /** * Returns the state of the shift key of the keyboard, if any. * @return true if the shift is in a pressed state, false otherwise. If there is * no shift key on the keyboard or there is no keyboard attached, it returns false. * @see KeyboardView#setShifted(boolean) */ public boolean isShifted() { if (mKeyboard != null) { return mKeyboard.isShifted(); } return false; } /** * Enables or disables the key feedback popup. This is a popup that shows a magnified * version of the depressed key. By default the preview is enabled. * @param previewEnabled whether or not to enable the key feedback popup * @see #isPreviewEnabled() */ public void setPreviewEnabled(boolean previewEnabled) { mShowPreview = previewEnabled; } /** * Returns the enabled state of the key feedback popup. * @return whether or not the key feedback popup is enabled * @see #setPreviewEnabled(boolean) */ public boolean isPreviewEnabled() { return mShowPreview; } public void setVerticalCorrection(int verticalOffset) { } public void setPopupParent(View v) { mPopupParent = v; } public void setPopupOffset(int x, int y) { mMiniKeyboardOffsetX = x; mMiniKeyboardOffsetY = y; if (mPreviewPopup.isShowing()) { mPreviewPopup.dismiss(); } } /** * When enabled, calls to {@link OnKeyboardActionListener#onKey} will include key * codes for adjacent keys. When disabled, only the primary key code will be * reported. * @param enabled whether or not the proximity correction is enabled */ public void setProximityCorrectionEnabled(boolean enabled) { mProximityCorrectOn = enabled; } /** * Returns true if proximity correction is enabled. */ public boolean isProximityCorrectionEnabled() { return mProximityCorrectOn; } /** * Popup keyboard close button clicked. * @hide */ public void onClick(View v) { dismissPopupKeyboard(); } private CharSequence adjustCase(CharSequence label) { if (mKeyboard.isShifted() && label != null && label.length() < 3 && Character.isLowerCase(label.charAt(0))) { label = label.toString().toUpperCase(); } return label; } @Override public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { // Round up a little if (mKeyboard == null) { setMeasuredDimension(mPaddingLeft + mPaddingRight, mPaddingTop + mPaddingBottom); } else { int width = mKeyboard.getMinWidth() + mPaddingLeft + mPaddingRight; if (MeasureSpec.getSize(widthMeasureSpec) < width + 10) { width = MeasureSpec.getSize(widthMeasureSpec); } setMeasuredDimension(width, mKeyboard.getHeight() + mPaddingTop + mPaddingBottom); } } /** * Compute the average distance between adjacent keys (horizontally and vertically) * and square it to get the proximity threshold. We use a square here and in computing * the touch distance from a key's center to avoid taking a square root. * @param keyboard */ private void computeProximityThreshold(Keyboard keyboard) { if (keyboard == null) return; final Key[] keys = mKeys; if (keys == null) return; int length = keys.length; int dimensionSum = 0; for (int i = 0; i < length; i++) { Key key = keys[i]; dimensionSum += Math.min(key.width, key.height) + key.gap; } if (dimensionSum < 0 || length == 0) return; mProximityThreshold = (int) (dimensionSum * 1.4f / length); mProximityThreshold *= mProximityThreshold; // Square it } @Override public void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); if (mKeyboard != null) { mKeyboard.resize(w, h); } // Release the buffer, if any and it will be reallocated on the next draw mBuffer = null; } @Override public void onDraw(Canvas canvas) { super.onDraw(canvas); if (mDrawPending || mBuffer == null || mKeyboardChanged) { onBufferDraw(); } canvas.drawBitmap(mBuffer, 0, 0, null); } private void onBufferDraw() { if (mBuffer == null || mKeyboardChanged) { if (mBuffer == null || mKeyboardChanged && (mBuffer.getWidth() != getWidth() || mBuffer.getHeight() != getHeight())) { // Make sure our bitmap is at least 1x1 final int width = Math.max(1, getWidth()); final int height = Math.max(1, getHeight()); mBuffer = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888); mCanvas = new Canvas(mBuffer); } invalidateAllKeys(); mKeyboardChanged = false; } if (mKeyboard == null) return; mCanvas.save(); final Canvas canvas = mCanvas; canvas.clipRect(mDirtyRect); final Paint paint = mPaint; final Drawable keyBackground = mKeyBackground; final Rect clipRegion = mClipRegion; final Rect padding = mPadding; final int kbdPaddingLeft = mPaddingLeft; final int kbdPaddingTop = mPaddingTop; final Key[] keys = mKeys; final Key invalidKey = mInvalidatedKey; paint.setColor(mKeyTextColor); boolean drawSingleKey = false; if (invalidKey != null && canvas.getClipBounds(clipRegion)) { // Is clipRegion completely contained within the invalidated key? if (invalidKey.x + kbdPaddingLeft - 1 <= clipRegion.left && invalidKey.y + kbdPaddingTop - 1 <= clipRegion.top && invalidKey.x + invalidKey.width + kbdPaddingLeft + 1 >= clipRegion.right && invalidKey.y + invalidKey.height + kbdPaddingTop + 1 >= clipRegion.bottom) { drawSingleKey = true; } } canvas.drawColor(0x00000000, PorterDuff.Mode.CLEAR); final int keyCount = keys.length; for (int i = 0; i < keyCount; i++) { final Key key = keys[i]; if (drawSingleKey && invalidKey != key) { continue; } int[] drawableState = key.getCurrentDrawableState(); keyBackground.setState(drawableState); // Switch the character to uppercase if shift is pressed String label = key.label == null ? null : adjustCase(key.label).toString(); final Rect bounds = keyBackground.getBounds(); if (key.width != bounds.right || key.height != bounds.bottom) { keyBackground.setBounds(0, 0, key.width, key.height); } canvas.translate(key.x + kbdPaddingLeft, key.y + kbdPaddingTop); keyBackground.draw(canvas); if (label != null) { // For characters, use large font. For labels like "Done", use small font. if (label.length() > 1 && key.codes.length < 2) { paint.setTextSize(mLabelTextSize); paint.setTypeface(Typeface.DEFAULT_BOLD); } else { paint.setTextSize(mKeyTextSize); paint.setTypeface(Typeface.DEFAULT); } // Draw a drop shadow for the text paint.setShadowLayer(mShadowRadius, 0, 0, mShadowColor); // Draw the text canvas.drawText(label, (key.width - padding.left - padding.right) / 2 + padding.left, (key.height - padding.top - padding.bottom) / 2 + (paint.getTextSize() - paint.descent()) / 2 + padding.top, paint); // Turn off drop shadow paint.setShadowLayer(0, 0, 0, 0); } else if (key.icon != null) { final int drawableX = (key.width - padding.left - padding.right - key.icon.getIntrinsicWidth()) / 2 + padding.left; final int drawableY = (key.height - padding.top - padding.bottom - key.icon.getIntrinsicHeight()) / 2 + padding.top; canvas.translate(drawableX, drawableY); key.icon.setBounds(0, 0, key.icon.getIntrinsicWidth(), key.icon.getIntrinsicHeight()); key.icon.draw(canvas); canvas.translate(-drawableX, -drawableY); } canvas.translate(-key.x - kbdPaddingLeft, -key.y - kbdPaddingTop); } mInvalidatedKey = null; // Overlay a dark rectangle to dim the keyboard if (mMiniKeyboardOnScreen) { paint.setColor((int) (mBackgroundDimAmount * 0xFF) << 24); canvas.drawRect(0, 0, getWidth(), getHeight(), paint); } if (DEBUG && mShowTouchPoints) { paint.setAlpha(128); paint.setColor(0xFFFF0000); canvas.drawCircle(mStartX, mStartY, 3, paint); canvas.drawLine(mStartX, mStartY, mLastX, mLastY, paint); paint.setColor(0xFF0000FF); canvas.drawCircle(mLastX, mLastY, 3, paint); paint.setColor(0xFF00FF00); canvas.drawCircle((mStartX + mLastX) / 2, (mStartY + mLastY) / 2, 2, paint); } mCanvas.restore(); mDrawPending = false; mDirtyRect.setEmpty(); } private int getKeyIndices(int x, int y, int[] allKeys) { final Key[] keys = mKeys; int primaryIndex = NOT_A_KEY; int closestKey = NOT_A_KEY; int closestKeyDist = mProximityThreshold + 1; java.util.Arrays.fill(mDistances, Integer.MAX_VALUE); int[] nearestKeyIndices = mKeyboard.getNearestKeys(x, y); final int keyCount = nearestKeyIndices.length; for (int i = 0; i < keyCount; i++) { final Key key = keys[nearestKeyIndices[i]]; int dist = 0; boolean isInside = key.isInside(x, y); if (isInside) { primaryIndex = nearestKeyIndices[i]; } if (((mProximityCorrectOn && (dist = key.squaredDistanceFrom(x, y)) < mProximityThreshold) || isInside) && key.codes[0] > 32) { // Find insertion point final int nCodes = key.codes.length; if (dist < closestKeyDist) { closestKeyDist = dist; closestKey = nearestKeyIndices[i]; } if (allKeys == null) continue; for (int j = 0; j < mDistances.length; j++) { if (mDistances[j] > dist) { // Make space for nCodes codes System.arraycopy(mDistances, j, mDistances, j + nCodes, mDistances.length - j - nCodes); System.arraycopy(allKeys, j, allKeys, j + nCodes, allKeys.length - j - nCodes); for (int c = 0; c < nCodes; c++) { allKeys[j + c] = key.codes[c]; mDistances[j + c] = dist; } break; } } } } if (primaryIndex == NOT_A_KEY) { primaryIndex = closestKey; } return primaryIndex; } private void detectAndSendKey(int index, int x, int y, long eventTime) { if (index != NOT_A_KEY && index < mKeys.length) { final Key key = mKeys[index]; if (key.text != null) { mKeyboardActionListener.onText(key.text); mKeyboardActionListener.onRelease(NOT_A_KEY); } else { int code = key.codes[0]; //TextEntryState.keyPressedAt(key, x, y); int[] codes = new int[MAX_NEARBY_KEYS]; Arrays.fill(codes, NOT_A_KEY); getKeyIndices(x, y, codes); // Multi-tap if (mInMultiTap) { if (mTapCount != -1) { mKeyboardActionListener.onKey(Keyboard.KEYCODE_DELETE, KEY_DELETE); } else { mTapCount = 0; } code = key.codes[mTapCount]; } mKeyboardActionListener.onKey(code, codes); mKeyboardActionListener.onRelease(code); } mLastSentIndex = index; mLastTapTime = eventTime; } } /** * Handle multi-tap keys by producing the key label for the current multi-tap state. */ private CharSequence getPreviewText(Key key) { if (mInMultiTap) { // Multi-tap mPreviewLabel.setLength(0); mPreviewLabel.append((char) key.codes[mTapCount < 0 ? 0 : mTapCount]); return adjustCase(mPreviewLabel); } else { return adjustCase(key.label); } } private void showPreview(int keyIndex) { int oldKeyIndex = mCurrentKeyIndex; final PopupWindow previewPopup = mPreviewPopup; mCurrentKeyIndex = keyIndex; // Release the old key and press the new key final Key[] keys = mKeys; if (oldKeyIndex != mCurrentKeyIndex) { if (oldKeyIndex != NOT_A_KEY && keys.length > oldKeyIndex) { Key oldKey = keys[oldKeyIndex]; oldKey.onReleased(mCurrentKeyIndex == NOT_A_KEY); invalidateKey(oldKeyIndex); final int keyCode = oldKey.codes[0]; sendAccessibilityEventForUnicodeCharacter(AccessibilityEvent.TYPE_VIEW_HOVER_EXIT, keyCode); // TODO: We need to implement AccessibilityNodeProvider for this view. sendAccessibilityEventForUnicodeCharacter(AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUS_CLEARED, keyCode); } if (mCurrentKeyIndex != NOT_A_KEY && keys.length > mCurrentKeyIndex) { Key newKey = keys[mCurrentKeyIndex]; newKey.onPressed(); invalidateKey(mCurrentKeyIndex); final int keyCode = newKey.codes[0]; sendAccessibilityEventForUnicodeCharacter(AccessibilityEvent.TYPE_VIEW_HOVER_ENTER, keyCode); // TODO: We need to implement AccessibilityNodeProvider for this view. sendAccessibilityEventForUnicodeCharacter(AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED, keyCode); } } // If key changed and preview is on ... if (oldKeyIndex != mCurrentKeyIndex && mShowPreview) { mHandler.removeMessages(MSG_SHOW_PREVIEW); if (previewPopup.isShowing()) { if (keyIndex == NOT_A_KEY) { mHandler.sendMessageDelayed(mHandler.obtainMessage(MSG_REMOVE_PREVIEW), DELAY_AFTER_PREVIEW); } } if (keyIndex != NOT_A_KEY) { if (previewPopup.isShowing() && mPreviewText.getVisibility() == VISIBLE) { // Show right away, if it's already visible and finger is moving around showKey(keyIndex); } else { mHandler.sendMessageDelayed(mHandler.obtainMessage(MSG_SHOW_PREVIEW, keyIndex, 0), DELAY_BEFORE_PREVIEW); } } } } @UnsupportedAppUsage private void showKey(final int keyIndex) { final PopupWindow previewPopup = mPreviewPopup; final Key[] keys = mKeys; if (keyIndex < 0 || keyIndex >= mKeys.length) return; Key key = keys[keyIndex]; if (key.icon != null) { mPreviewText.setCompoundDrawables(null, null, null, key.iconPreview != null ? key.iconPreview : key.icon); mPreviewText.setText(null); } else { mPreviewText.setCompoundDrawables(null, null, null, null); mPreviewText.setText(getPreviewText(key)); if (key.label.length() > 1 && key.codes.length < 2) { mPreviewText.setTextSize(TypedValue.COMPLEX_UNIT_PX, mKeyTextSize); mPreviewText.setTypeface(Typeface.DEFAULT_BOLD); } else { mPreviewText.setTextSize(TypedValue.COMPLEX_UNIT_PX, mPreviewTextSizeLarge); mPreviewText.setTypeface(Typeface.DEFAULT); } } mPreviewText.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED)); int popupWidth = Math.max(mPreviewText.getMeasuredWidth(), key.width + mPreviewText.getPaddingLeft() + mPreviewText.getPaddingRight()); final int popupHeight = mPreviewHeight; LayoutParams lp = mPreviewText.getLayoutParams(); if (lp != null) { lp.width = popupWidth; lp.height = popupHeight; } if (!mPreviewCentered) { mPopupPreviewX = key.x - mPreviewText.getPaddingLeft() + mPaddingLeft; mPopupPreviewY = key.y - popupHeight + mPreviewOffset; } else { // TODO: Fix this if centering is brought back mPopupPreviewX = 160 - mPreviewText.getMeasuredWidth() / 2; mPopupPreviewY = -mPreviewText.getMeasuredHeight(); } mHandler.removeMessages(MSG_REMOVE_PREVIEW); getLocationInWindow(mCoordinates); mCoordinates[0] += mMiniKeyboardOffsetX; // Offset may be zero mCoordinates[1] += mMiniKeyboardOffsetY; // Offset may be zero // Set the preview background state mPreviewText.getBackground().setState(key.popupResId != 0 ? LONG_PRESSABLE_STATE_SET : EMPTY_STATE_SET); mPopupPreviewX += mCoordinates[0]; mPopupPreviewY += mCoordinates[1]; // If the popup cannot be shown above the key, put it on the side getLocationOnScreen(mCoordinates); if (mPopupPreviewY + mCoordinates[1] < 0) { // If the key you're pressing is on the left side of the keyboard, show the popup on // the right, offset by enough to see at least one key to the left/right. if (key.x + key.width <= getWidth() / 2) { mPopupPreviewX += (int) (key.width * 2.5); } else { mPopupPreviewX -= (int) (key.width * 2.5); } mPopupPreviewY += popupHeight; } if (previewPopup.isShowing()) { previewPopup.update(mPopupPreviewX, mPopupPreviewY, popupWidth, popupHeight); } else { previewPopup.setWidth(popupWidth); previewPopup.setHeight(popupHeight); previewPopup.showAtLocation(mPopupParent, Gravity.NO_GRAVITY, mPopupPreviewX, mPopupPreviewY); } mPreviewText.setVisibility(VISIBLE); } private void sendAccessibilityEventForUnicodeCharacter(int eventType, int code) { if (mAccessibilityManager.isEnabled()) { AccessibilityEvent event = AccessibilityEvent.obtain(eventType); onInitializeAccessibilityEvent(event); final String text; switch (code) { case Keyboard.KEYCODE_ALT: text = mContext.getString(R.string.keyboardview_keycode_alt); break; case Keyboard.KEYCODE_CANCEL: text = mContext.getString(R.string.keyboardview_keycode_cancel); break; case Keyboard.KEYCODE_DELETE: text = mContext.getString(R.string.keyboardview_keycode_delete); break; case Keyboard.KEYCODE_DONE: text = mContext.getString(R.string.keyboardview_keycode_done); break; case Keyboard.KEYCODE_MODE_CHANGE: text = mContext.getString(R.string.keyboardview_keycode_mode_change); break; case Keyboard.KEYCODE_SHIFT: text = mContext.getString(R.string.keyboardview_keycode_shift); break; case '\n': text = mContext.getString(R.string.keyboardview_keycode_enter); break; default: text = String.valueOf((char) code); } event.getText().add(text); mAccessibilityManager.sendAccessibilityEvent(event); } } /** * Requests a redraw of the entire keyboard. Calling {@link #invalidate} is not sufficient * because the keyboard renders the keys to an off-screen buffer and an invalidate() only * draws the cached buffer. * @see #invalidateKey(int) */ public void invalidateAllKeys() { mDirtyRect.union(0, 0, getWidth(), getHeight()); mDrawPending = true; invalidate(); } /** * Invalidates a key so that it will be redrawn on the next repaint. Use this method if only * one key is changing it's content. Any changes that affect the position or size of the key * may not be honored. * @param keyIndex the index of the key in the attached {@link Keyboard}. * @see #invalidateAllKeys */ public void invalidateKey(int keyIndex) { if (mKeys == null) return; if (keyIndex < 0 || keyIndex >= mKeys.length) { return; } final Key key = mKeys[keyIndex]; mInvalidatedKey = key; mDirtyRect.union(key.x + mPaddingLeft, key.y + mPaddingTop, key.x + key.width + mPaddingLeft, key.y + key.height + mPaddingTop); onBufferDraw(); invalidate(key.x + mPaddingLeft, key.y + mPaddingTop, key.x + key.width + mPaddingLeft, key.y + key.height + mPaddingTop); } @UnsupportedAppUsage private boolean openPopupIfRequired(MotionEvent me) { // Check if we have a popup layout specified first. if (mPopupLayout == 0) { return false; } if (mCurrentKey < 0 || mCurrentKey >= mKeys.length) { return false; } Key popupKey = mKeys[mCurrentKey]; boolean result = onLongPress(popupKey); if (result) { mAbortKey = true; showPreview(NOT_A_KEY); } return result; } /** * Called when a key is long pressed. By default this will open any popup keyboard associated * with this key through the attributes popupLayout and popupCharacters. * @param popupKey the key that was long pressed * @return true if the long press is handled, false otherwise. Subclasses should call the * method on the base class if the subclass doesn't wish to handle the call. */ protected boolean onLongPress(Key popupKey) { int popupKeyboardId = popupKey.popupResId; if (popupKeyboardId != 0) { mMiniKeyboardContainer = mMiniKeyboardCache.get(popupKey); if (mMiniKeyboardContainer == null) { LayoutInflater inflater = (LayoutInflater) getContext() .getSystemService(Context.LAYOUT_INFLATER_SERVICE); mMiniKeyboardContainer = inflater.inflate(mPopupLayout, null); mMiniKeyboard = (KeyboardView) mMiniKeyboardContainer .findViewById(com.android.internal.R.id.keyboardView); View closeButton = mMiniKeyboardContainer.findViewById(com.android.internal.R.id.closeButton); if (closeButton != null) closeButton.setOnClickListener(this); mMiniKeyboard.setOnKeyboardActionListener(new OnKeyboardActionListener() { public void onKey(int primaryCode, int[] keyCodes) { mKeyboardActionListener.onKey(primaryCode, keyCodes); dismissPopupKeyboard(); } public void onText(CharSequence text) { mKeyboardActionListener.onText(text); dismissPopupKeyboard(); } public void swipeLeft() { } public void swipeRight() { } public void swipeUp() { } public void swipeDown() { } public void onPress(int primaryCode) { mKeyboardActionListener.onPress(primaryCode); } public void onRelease(int primaryCode) { mKeyboardActionListener.onRelease(primaryCode); } }); //mInputView.setSuggest(mSuggest); Keyboard keyboard; if (popupKey.popupCharacters != null) { keyboard = new Keyboard(getContext(), popupKeyboardId, popupKey.popupCharacters, -1, getPaddingLeft() + getPaddingRight()); } else { keyboard = new Keyboard(getContext(), popupKeyboardId); } mMiniKeyboard.setKeyboard(keyboard); mMiniKeyboard.setPopupParent(this); mMiniKeyboardContainer.measure(MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.AT_MOST), MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.AT_MOST)); mMiniKeyboardCache.put(popupKey, mMiniKeyboardContainer); } else { mMiniKeyboard = (KeyboardView) mMiniKeyboardContainer .findViewById(com.android.internal.R.id.keyboardView); } getLocationInWindow(mCoordinates); mPopupX = popupKey.x + mPaddingLeft; mPopupY = popupKey.y + mPaddingTop; mPopupX = mPopupX + popupKey.width - mMiniKeyboardContainer.getMeasuredWidth(); mPopupY = mPopupY - mMiniKeyboardContainer.getMeasuredHeight(); final int x = mPopupX + mMiniKeyboardContainer.getPaddingRight() + mCoordinates[0]; final int y = mPopupY + mMiniKeyboardContainer.getPaddingBottom() + mCoordinates[1]; mMiniKeyboard.setPopupOffset(x < 0 ? 0 : x, y); mMiniKeyboard.setShifted(isShifted()); mPopupKeyboard.setContentView(mMiniKeyboardContainer); mPopupKeyboard.setWidth(mMiniKeyboardContainer.getMeasuredWidth()); mPopupKeyboard.setHeight(mMiniKeyboardContainer.getMeasuredHeight()); mPopupKeyboard.showAtLocation(this, Gravity.NO_GRAVITY, x, y); mMiniKeyboardOnScreen = true; //mMiniKeyboard.onTouchEvent(getTranslatedEvent(me)); invalidateAllKeys(); return true; } return false; } @Override public boolean onHoverEvent(MotionEvent event) { if (mAccessibilityManager.isTouchExplorationEnabled() && event.getPointerCount() == 1) { final int action = event.getAction(); switch (action) { case MotionEvent.ACTION_HOVER_ENTER: { event.setAction(MotionEvent.ACTION_DOWN); } break; case MotionEvent.ACTION_HOVER_MOVE: { event.setAction(MotionEvent.ACTION_MOVE); } break; case MotionEvent.ACTION_HOVER_EXIT: { event.setAction(MotionEvent.ACTION_UP); } break; } return onTouchEvent(event); } return true; } @Override public boolean onTouchEvent(MotionEvent me) { // Convert multi-pointer up/down events to single up/down events to // deal with the typical multi-pointer behavior of two-thumb typing final int pointerCount = me.getPointerCount(); final int action = me.getAction(); boolean result = false; final long now = me.getEventTime(); if (pointerCount != mOldPointerCount) { if (pointerCount == 1) { // Send a down event for the latest pointer MotionEvent down = MotionEvent.obtain(now, now, MotionEvent.ACTION_DOWN, me.getX(), me.getY(), me.getMetaState()); result = onModifiedTouchEvent(down, false); down.recycle(); // If it's an up action, then deliver the up as well. if (action == MotionEvent.ACTION_UP) { result = onModifiedTouchEvent(me, true); } } else { // Send an up event for the last pointer MotionEvent up = MotionEvent.obtain(now, now, MotionEvent.ACTION_UP, mOldPointerX, mOldPointerY, me.getMetaState()); result = onModifiedTouchEvent(up, true); up.recycle(); } } else { if (pointerCount == 1) { result = onModifiedTouchEvent(me, false); mOldPointerX = me.getX(); mOldPointerY = me.getY(); } else { // Don't do anything when 2 pointers are down and moving. result = true; } } mOldPointerCount = pointerCount; return result; } private boolean onModifiedTouchEvent(MotionEvent me, boolean possiblePoly) { int touchX = (int) me.getX() - mPaddingLeft; int touchY = (int) me.getY() - mPaddingTop; if (touchY >= -mVerticalCorrection) touchY += mVerticalCorrection; final int action = me.getAction(); final long eventTime = me.getEventTime(); int keyIndex = getKeyIndices(touchX, touchY, null); mPossiblePoly = possiblePoly; // Track the last few movements to look for spurious swipes. if (action == MotionEvent.ACTION_DOWN) mSwipeTracker.clear(); mSwipeTracker.addMovement(me); // Ignore all motion events until a DOWN. if (mAbortKey && action != MotionEvent.ACTION_DOWN && action != MotionEvent.ACTION_CANCEL) { return true; } if (mGestureDetector.onTouchEvent(me)) { showPreview(NOT_A_KEY); mHandler.removeMessages(MSG_REPEAT); mHandler.removeMessages(MSG_LONGPRESS); return true; } // Needs to be called after the gesture detector gets a turn, as it may have // displayed the mini keyboard if (mMiniKeyboardOnScreen && action != MotionEvent.ACTION_CANCEL) { return true; } switch (action) { case MotionEvent.ACTION_DOWN: mAbortKey = false; mStartX = touchX; mStartY = touchY; mLastCodeX = touchX; mLastCodeY = touchY; mLastKeyTime = 0; mCurrentKeyTime = 0; mLastKey = NOT_A_KEY; mCurrentKey = keyIndex; mDownKey = keyIndex; mDownTime = me.getEventTime(); mLastMoveTime = mDownTime; checkMultiTap(eventTime, keyIndex); mKeyboardActionListener.onPress(keyIndex != NOT_A_KEY ? mKeys[keyIndex].codes[0] : 0); if (mCurrentKey >= 0 && mKeys[mCurrentKey].repeatable) { mRepeatKeyIndex = mCurrentKey; Message msg = mHandler.obtainMessage(MSG_REPEAT); mHandler.sendMessageDelayed(msg, REPEAT_START_DELAY); repeatKey(); // Delivering the key could have caused an abort if (mAbortKey) { mRepeatKeyIndex = NOT_A_KEY; break; } } if (mCurrentKey != NOT_A_KEY) { Message msg = mHandler.obtainMessage(MSG_LONGPRESS, me); mHandler.sendMessageDelayed(msg, LONGPRESS_TIMEOUT); } showPreview(keyIndex); break; case MotionEvent.ACTION_MOVE: boolean continueLongPress = false; if (keyIndex != NOT_A_KEY) { if (mCurrentKey == NOT_A_KEY) { mCurrentKey = keyIndex; mCurrentKeyTime = eventTime - mDownTime; } else { if (keyIndex == mCurrentKey) { mCurrentKeyTime += eventTime - mLastMoveTime; continueLongPress = true; } else if (mRepeatKeyIndex == NOT_A_KEY) { resetMultiTap(); mLastKey = mCurrentKey; mLastCodeX = mLastX; mLastCodeY = mLastY; mLastKeyTime = mCurrentKeyTime + eventTime - mLastMoveTime; mCurrentKey = keyIndex; mCurrentKeyTime = 0; } } } if (!continueLongPress) { // Cancel old longpress mHandler.removeMessages(MSG_LONGPRESS); // Start new longpress if key has changed if (keyIndex != NOT_A_KEY) { Message msg = mHandler.obtainMessage(MSG_LONGPRESS, me); mHandler.sendMessageDelayed(msg, LONGPRESS_TIMEOUT); } } showPreview(mCurrentKey); mLastMoveTime = eventTime; break; case MotionEvent.ACTION_UP: removeMessages(); if (keyIndex == mCurrentKey) { mCurrentKeyTime += eventTime - mLastMoveTime; } else { resetMultiTap(); mLastKey = mCurrentKey; mLastKeyTime = mCurrentKeyTime + eventTime - mLastMoveTime; mCurrentKey = keyIndex; mCurrentKeyTime = 0; } if (mCurrentKeyTime < mLastKeyTime && mCurrentKeyTime < DEBOUNCE_TIME && mLastKey != NOT_A_KEY) { mCurrentKey = mLastKey; touchX = mLastCodeX; touchY = mLastCodeY; } showPreview(NOT_A_KEY); Arrays.fill(mKeyIndices, NOT_A_KEY); // If we're not on a repeating key (which sends on a DOWN event) if (mRepeatKeyIndex == NOT_A_KEY && !mMiniKeyboardOnScreen && !mAbortKey) { detectAndSendKey(mCurrentKey, touchX, touchY, eventTime); } invalidateKey(keyIndex); mRepeatKeyIndex = NOT_A_KEY; break; case MotionEvent.ACTION_CANCEL: removeMessages(); dismissPopupKeyboard(); mAbortKey = true; showPreview(NOT_A_KEY); invalidateKey(mCurrentKey); break; } mLastX = touchX; mLastY = touchY; return true; } @UnsupportedAppUsage private boolean repeatKey() { Key key = mKeys[mRepeatKeyIndex]; detectAndSendKey(mCurrentKey, key.x, key.y, mLastTapTime); return true; } protected void swipeRight() { mKeyboardActionListener.swipeRight(); } protected void swipeLeft() { mKeyboardActionListener.swipeLeft(); } protected void swipeUp() { mKeyboardActionListener.swipeUp(); } protected void swipeDown() { mKeyboardActionListener.swipeDown(); } public void closing() { if (mPreviewPopup.isShowing()) { mPreviewPopup.dismiss(); } removeMessages(); dismissPopupKeyboard(); mBuffer = null; mCanvas = null; mMiniKeyboardCache.clear(); } private void removeMessages() { if (mHandler != null) { mHandler.removeMessages(MSG_REPEAT); mHandler.removeMessages(MSG_LONGPRESS); mHandler.removeMessages(MSG_SHOW_PREVIEW); } } @Override public void onDetachedFromWindow() { super.onDetachedFromWindow(); closing(); } private void dismissPopupKeyboard() { if (mPopupKeyboard.isShowing()) { mPopupKeyboard.dismiss(); mMiniKeyboardOnScreen = false; invalidateAllKeys(); } } public boolean handleBack() { if (mPopupKeyboard.isShowing()) { dismissPopupKeyboard(); return true; } return false; } private void resetMultiTap() { mLastSentIndex = NOT_A_KEY; mTapCount = 0; mLastTapTime = -1; mInMultiTap = false; } private void checkMultiTap(long eventTime, int keyIndex) { if (keyIndex == NOT_A_KEY) return; Key key = mKeys[keyIndex]; if (key.codes.length > 1) { mInMultiTap = true; if (eventTime < mLastTapTime + MULTITAP_INTERVAL && keyIndex == mLastSentIndex) { mTapCount = (mTapCount + 1) % key.codes.length; return; } else { mTapCount = -1; return; } } if (eventTime > mLastTapTime + MULTITAP_INTERVAL || keyIndex != mLastSentIndex) { resetMultiTap(); } } private static class SwipeTracker { static final int NUM_PAST = 4; static final int LONGEST_PAST_TIME = 200; final float mPastX[] = new float[NUM_PAST]; final float mPastY[] = new float[NUM_PAST]; final long mPastTime[] = new long[NUM_PAST]; float mYVelocity; float mXVelocity; public void clear() { mPastTime[0] = 0; } public void addMovement(MotionEvent ev) { long time = ev.getEventTime(); final int N = ev.getHistorySize(); for (int i = 0; i < N; i++) { addPoint(ev.getHistoricalX(i), ev.getHistoricalY(i), ev.getHistoricalEventTime(i)); } addPoint(ev.getX(), ev.getY(), time); } private void addPoint(float x, float y, long time) { int drop = -1; int i; final long[] pastTime = mPastTime; for (i = 0; i < NUM_PAST; i++) { if (pastTime[i] == 0) { break; } else if (pastTime[i] < time - LONGEST_PAST_TIME) { drop = i; } } if (i == NUM_PAST && drop < 0) { drop = 0; } if (drop == i) drop--; final float[] pastX = mPastX; final float[] pastY = mPastY; if (drop >= 0) { final int start = drop + 1; final int count = NUM_PAST - drop - 1; System.arraycopy(pastX, start, pastX, 0, count); System.arraycopy(pastY, start, pastY, 0, count); System.arraycopy(pastTime, start, pastTime, 0, count); i -= (drop + 1); } pastX[i] = x; pastY[i] = y; pastTime[i] = time; i++; if (i < NUM_PAST) { pastTime[i] = 0; } } public void computeCurrentVelocity(int units) { computeCurrentVelocity(units, Float.MAX_VALUE); } public void computeCurrentVelocity(int units, float maxVelocity) { final float[] pastX = mPastX; final float[] pastY = mPastY; final long[] pastTime = mPastTime; final float oldestX = pastX[0]; final float oldestY = pastY[0]; final long oldestTime = pastTime[0]; float accumX = 0; float accumY = 0; int N = 0; while (N < NUM_PAST) { if (pastTime[N] == 0) { break; } N++; } for (int i = 1; i < N; i++) { final int dur = (int) (pastTime[i] - oldestTime); if (dur == 0) continue; float dist = pastX[i] - oldestX; float vel = (dist / dur) * units; // pixels/frame. if (accumX == 0) accumX = vel; else accumX = (accumX + vel) * .5f; dist = pastY[i] - oldestY; vel = (dist / dur) * units; // pixels/frame. if (accumY == 0) accumY = vel; else accumY = (accumY + vel) * .5f; } mXVelocity = accumX < 0.0f ? Math.max(accumX, -maxVelocity) : Math.min(accumX, maxVelocity); mYVelocity = accumY < 0.0f ? Math.max(accumY, -maxVelocity) : Math.min(accumY, maxVelocity); } public float getXVelocity() { return mXVelocity; } public float getYVelocity() { return mYVelocity; } } }