diff options
Diffstat (limited to 'java/src/com/android/inputmethod/keyboard/KeyDetector.java')
| -rw-r--r-- | java/src/com/android/inputmethod/keyboard/KeyDetector.java | 177 |
1 files changed, 47 insertions, 130 deletions
diff --git a/java/src/com/android/inputmethod/keyboard/KeyDetector.java b/java/src/com/android/inputmethod/keyboard/KeyDetector.java index 7add43a6d..13e909c7e 100644 --- a/java/src/com/android/inputmethod/keyboard/KeyDetector.java +++ b/java/src/com/android/inputmethod/keyboard/KeyDetector.java @@ -16,28 +16,26 @@ package com.android.inputmethod.keyboard; -import android.util.Log; - -import java.util.Arrays; -import java.util.List; public class KeyDetector { - private static final String TAG = KeyDetector.class.getSimpleName(); - private static final boolean DEBUG = false; - public static final int NOT_A_CODE = -1; - public static final int NOT_A_KEY = -1; + + private final int mKeyHysteresisDistanceSquared; private Keyboard mKeyboard; private int mCorrectionX; private int mCorrectionY; private boolean mProximityCorrectOn; - private int mProximityThresholdSquare; - // working area - private static final int MAX_NEARBY_KEYS = 12; - private final int[] mDistances = new int[MAX_NEARBY_KEYS]; - private final int[] mIndices = new int[MAX_NEARBY_KEYS]; + /** + * This class handles key detection. + * + * @param keyHysteresisDistance if the pointer movement distance is smaller than this, the + * movement will not been handled as meaningful movement. The unit is pixel. + */ + public KeyDetector(float keyHysteresisDistance) { + mKeyHysteresisDistanceSquared = (int)(keyHysteresisDistance * keyHysteresisDistance); + } public void setKeyboard(Keyboard keyboard, float correctionX, float correctionY) { if (keyboard == null) @@ -47,19 +45,22 @@ public class KeyDetector { mKeyboard = keyboard; } - protected int getTouchX(int x) { + public int getKeyHysteresisDistanceSquared() { + return mKeyHysteresisDistanceSquared; + } + + public int getTouchX(int x) { return x + mCorrectionX; } - protected int getTouchY(int y) { + public int getTouchY(int y) { return y + mCorrectionY; } - protected List<Key> getKeys() { + public Keyboard getKeyboard() { if (mKeyboard == null) throw new IllegalStateException("keyboard isn't set"); - // mKeyboard is guaranteed not to be null at setKeybaord() method if mKeys is not null - return mKeyboard.getKeys(); + return mKeyboard; } public void setProximityCorrectionEnabled(boolean enabled) { @@ -70,133 +71,49 @@ public class KeyDetector { return mProximityCorrectOn; } - public void setProximityThreshold(int threshold) { - mProximityThresholdSquare = threshold * threshold; - } - - /** - * Computes maximum size of the array that can contain all nearby key indices returned by - * {@link #getKeyIndexAndNearbyCodes}. - * - * @return Returns maximum size of the array that can contain all nearby key indices returned - * by {@link #getKeyIndexAndNearbyCodes}. - */ - protected int getMaxNearbyKeys() { - return MAX_NEARBY_KEYS; + public boolean alwaysAllowsSlidingInput() { + return false; } /** - * Allocates array that can hold all key indices returned by {@link #getKeyIndexAndNearbyCodes} - * method. The maximum size of the array should be computed by {@link #getMaxNearbyKeys}. - * - * @return Allocates and returns an array that can hold all key indices returned by - * {@link #getKeyIndexAndNearbyCodes} method. All elements in the returned array are - * initialized by {@link #NOT_A_CODE} value. - */ - public int[] newCodeArray() { - int[] codes = new int[getMaxNearbyKeys()]; - Arrays.fill(codes, NOT_A_CODE); - return codes; - } - - private void initializeNearbyKeys() { - Arrays.fill(mDistances, Integer.MAX_VALUE); - Arrays.fill(mIndices, NOT_A_KEY); - } - - /** - * Insert the key into nearby keys buffer and sort nearby keys by ascending order of distance. - * If the distance of two keys are the same, the key which the point is on should be considered - * as a closer one. - * - * @param keyIndex index of the key. - * @param distance distance between the key's edge and user touched point. - * @param isOnKey true if the point is on the key. - * @return order of the key in the nearby buffer, 0 if it is the nearest key. - */ - private int sortNearbyKeys(int keyIndex, int distance, boolean isOnKey) { - final int[] distances = mDistances; - final int[] indices = mIndices; - for (int insertPos = 0; insertPos < distances.length; insertPos++) { - final int comparingDistance = distances[insertPos]; - if (distance < comparingDistance || (distance == comparingDistance && isOnKey)) { - final int nextPos = insertPos + 1; - if (nextPos < distances.length) { - System.arraycopy(distances, insertPos, distances, nextPos, - distances.length - nextPos); - System.arraycopy(indices, insertPos, indices, nextPos, - indices.length - nextPos); - } - distances[insertPos] = distance; - indices[insertPos] = keyIndex; - return insertPos; - } - } - return distances.length; - } - - private void getNearbyKeyCodes(final int[] allCodes) { - final List<Key> keys = getKeys(); - final int[] indices = mIndices; - - // allCodes[0] should always have the key code even if it is a non-letter key. - if (indices[0] == NOT_A_KEY) { - allCodes[0] = NOT_A_CODE; - return; - } - - int numCodes = 0; - for (int j = 0; j < indices.length && numCodes < allCodes.length; j++) { - final int index = indices[j]; - if (index == NOT_A_KEY) - break; - final int code = keys.get(index).mCode; - // filter out a non-letter key from nearby keys - if (code < Keyboard.CODE_SPACE) - continue; - allCodes[numCodes++] = code; - } - } - - /** - * Finds all possible nearby key indices around a touch event point and returns the nearest key - * index. The algorithm to determine the nearby keys depends on the threshold set by - * {@link #setProximityThreshold(int)} and the mode set by - * {@link #setProximityCorrectionEnabled(boolean)}. + * Detect the key whose hitbox the touch point is in. * * @param x The x-coordinate of a touch point * @param y The y-coordinate of a touch point - * @param allCodes All nearby key code except functional key are returned in this array - * @return The nearest key index + * @return the key that the touch point hits. */ - public int getKeyIndexAndNearbyCodes(int x, int y, final int[] allCodes) { - final List<Key> keys = getKeys(); + public Key detectHitKey(int x, int y) { final int touchX = getTouchX(x); final int touchY = getTouchY(y); - initializeNearbyKeys(); - int primaryIndex = NOT_A_KEY; - for (final int index : mKeyboard.getNearestKeys(touchX, touchY)) { - final Key key = keys.get(index); + int minDistance = Integer.MAX_VALUE; + Key primaryKey = null; + for (final Key key: mKeyboard.getNearestKeys(touchX, touchY)) { final boolean isOnKey = key.isOnKey(touchX, touchY); final int distance = key.squaredDistanceToEdge(touchX, touchY); - if (isOnKey || (mProximityCorrectOn && distance < mProximityThresholdSquare)) { - final int insertedPosition = sortNearbyKeys(index, distance, isOnKey); - if (insertedPosition == 0 && isOnKey) - primaryIndex = index; + // To take care of hitbox overlaps, we compare mCode here too. + if (primaryKey == null || distance < minDistance + || (distance == minDistance && isOnKey && key.mCode > primaryKey.mCode)) { + minDistance = distance; + primaryKey = key; } } + return primaryKey; + } - if (allCodes != null && allCodes.length > 0) { - getNearbyKeyCodes(allCodes); - if (DEBUG) { - Log.d(TAG, "x=" + x + " y=" + y - + " primary=" - + (primaryIndex == NOT_A_KEY ? "none" : keys.get(primaryIndex).mCode) - + " codes=" + Arrays.toString(allCodes)); - } - } + public static String printableCode(Key key) { + return key != null ? Keyboard.printableCode(key.mCode) : "none"; + } - return primaryIndex; + public static String printableCodes(int[] codes) { + final StringBuilder sb = new StringBuilder(); + boolean addDelimiter = false; + for (final int code : codes) { + if (code == NOT_A_CODE) break; + if (addDelimiter) sb.append(", "); + sb.append(Keyboard.printableCode(code)); + addDelimiter = true; + } + return "[" + sb + "]"; } } |