【学习Android】Keyboard.class类源码注解
阚英睿
为了自己学习方便，对Android的部分源码原样粘贴在这里，然后自己编辑，用中文注释了一下。不是原创代码。
/*
* 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 org.xmlpull.v1.XmlPullParserException;
import android.content.Context;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.content.res.XmlResourceParser;
import android.graphics.drawable.Drawable;
import android.text.TextUtils;
import android.util.Log;
import android.util.TypedValue;
import android.util.Xml;
import android.util.DisplayMetrics;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;
/**
* class Keyboard：该类的作用就是 加载一个描述键盘的XML文件、储存其中键的属性。
* Loads an XML description of a keyboard and stores the attributes of the keys.
* A keyboard consists of rows of keys.
* <p>The layout file for a keyboard contains XML that looks like the following snippet:</p>
* <pre>
* <Keyboard
* android:keyWidth="%10p"
* android:keyHeight="50px"
* android:horizontalGap="2px"
* android:verticalGap="2px" >
* <Row android:keyWidth="32px" >
* <Key android:keyLabel="A" />
* ...
* </Row>
* ...
* </Keyboard>
* </pre>
* @attr ref android.R.styleable#Keyboard_keyWidth
* @attr ref android.R.styleable#Keyboard_keyHeight
* @attr ref android.R.styleable#Keyboard_horizontalGap
* @attr ref android.R.styleable#Keyboard_verticalGap
*/
public class Keyboard {
static final String TAG = "Keyboard";
// Keyboard XML Tags（XML的标签，常量）
private static final String TAG_KEYBOARD = "Keyboard";
private static final String TAG_ROW = "Row";
private static final String TAG_KEY = "Key";
public static final int EDGE_LEFT = 0x01;
public static final int EDGE_RIGHT = 0x02;
public static final int EDGE_TOP = 0x04;
public static final int EDGE_BOTTOM = 0x08;
public static final int KEYCODE_SHIFT = -1;
public static final int KEYCODE_MODE_CHANGE = -2;
public static final int KEYCODE_CANCEL = -3;
public static final int KEYCODE_DONE = -4;
public static final int KEYCODE_DELETE = -5;
public static final int KEYCODE_ALT = -6;
/** Keyboard label（键的标签，UI上显示的字符，变量） **/
private CharSequence mLabel;
/** Horizontal gap default for all rows */
private int mDefaultHorizontalGap;
/** Default key width */
private int mDefaultWidth;
/** Default key height */
private int mDefaultHeight;
/** Default gap between rows */
private int mDefaultVerticalGap;
/** Is the keyboard in the shifted state */
private boolean mShifted;
/** Key instance for the shift key, if present */
private Key[] mShiftKeys = { null, null };
/** Key index for the shift key, if present */
private int[] mShiftKeyIndices = {-1, -1};
/** Current key width, while loading the keyboard */
private int mKeyWidth;
/** Current key height, while loading the keyboard */
private int mKeyHeight;
/** Total height of the keyboard, including the padding and keys */
private int mTotalHeight;
/**
* Total width of the keyboard, including left side gaps and keys, but not any gaps on the
* right side.
*/
private int mTotalWidth;
/** List of keys in this keyboard */
private List<Key> mKeys;
/** List of modifier keys such as Shift & Alt, if any */
private List<Key> mModifierKeys;
/** Width of the screen available to fit the keyboard */
private int mDisplayWidth;
/** Height of the screen */
private int mDisplayHeight;
/** Keyboard mode, or zero, if none. */
private int mKeyboardMode;
// Variables for pre-computing nearest keys.
private static final int GRID_WIDTH = 10;
private static final int GRID_HEIGHT = 5;
private static final int GRID_SIZE = GRID_WIDTH * GRID_HEIGHT;
private int mCellWidth;
private int mCellHeight;
private int[][] mGridNeighbors;
private int mProximityThreshold;
/** Number of key widths from current touch point to search for nearest keys. */
private static float SEARCH_DISTANCE = 1.8f;
private ArrayList<Row> rows = new ArrayList<Row>();
/**
* class Row ：定义每一行键的特征
* Container for keys in the keyboard.（键盘中键的容器） All keys in a row are at the same Y-coordinate.
* Some of the key size defaults can be overridden per row from what the {@link Keyboard}defines.
* @attr ref android.R.styleable#Keyboard_keyWidth
* @attr ref android.R.styleable#Keyboard_keyHeight
* @attr ref android.R.styleable#Keyboard_horizontalGap
* @attr ref android.R.styleable#Keyboard_verticalGap
* @attr ref android.R.styleable#Keyboard_Row_rowEdgeFlags
* @attr ref android.R.styleable#Keyboard_Row_keyboardMode
*/
public static class Row {
/** Default width of a key in this row. */
public int defaultWidth;
/** Default height of a key in this row. */
public int defaultHeight;
/** Default horizontal gap between keys in this row. */
public int defaultHorizontalGap;
/** Vertical gap following this row. */
public int verticalGap;
ArrayList<Key> mKeys = new ArrayList<Key>();
/**
* Edge flags for this row of keys. Possible values that can be assigned are
* {@link Keyboard#EDGE_TOP EDGE_TOP} and {@link Keyboard#EDGE_BOTTOM EDGE_BOTTOM}
*/
public int rowEdgeFlags;
/** The keyboard mode for this row */
public int mode;
private Keyboard parent;
public Row(Keyboard parent) {
this.parent = parent;
}
public Row(Resources res, Keyboard parent, XmlResourceParser parser) {//Xml资源解析器
this.parent = parent;
TypedArray a = res.obtainAttributes(Xml.asAttributeSet(parser),
com.android.internal.R.styleable.Keyboard);
defaultWidth = getDimensionOrFraction(a,
com.android.internal.R.styleable.Keyboard_keyWidth,
parent.mDisplayWidth, parent.mDefaultWidth);
defaultHeight = getDimensionOrFraction(a,
com.android.internal.R.styleable.Keyboard_keyHeight,
parent.mDisplayHeight, parent.mDefaultHeight);
defaultHorizontalGap = getDimensionOrFraction(a,
com.android.internal.R.styleable.Keyboard_horizontalGap,
parent.mDisplayWidth, parent.mDefaultHorizontalGap);
verticalGap = getDimensionOrFraction(a,
com.android.internal.R.styleable.Keyboard_verticalGap,
parent.mDisplayHeight, parent.mDefaultVerticalGap);
a.recycle();
a = res.obtainAttributes(Xml.asAttributeSet(parser),
com.android.internal.R.styleable.Keyboard_Row);
rowEdgeFlags = a.getInt(com.android.internal.R.styleable.Keyboard_Row_rowEdgeFlags, 0);
mode = a.getResourceId(com.android.internal.R.styleable.Keyboard_Row_keyboardMode,
0);
}
}
/**
* class Key：定义单个键的位置和特征
* Class for describing the position and characteristics of a single key in the keyboard.
* @attr ref android.R.styleable#Keyboard_keyWidth
* @attr ref android.R.styleable#Keyboard_keyHeight
* @attr ref android.R.styleable#Keyboard_horizontalGap
* @attr ref android.R.styleable#Keyboard_Key_codes
* @attr ref android.R.styleable#Keyboard_Key_keyIcon
* @attr ref android.R.styleable#Keyboard_Key_keyLabel
* @attr ref android.R.styleable#Keyboard_Key_iconPreview
* @attr ref android.R.styleable#Keyboard_Key_isSticky
* @attr ref android.R.styleable#Keyboard_Key_isRepeatable
* @attr ref android.R.styleable#Keyboard_Key_isModifier
* @attr ref android.R.styleable#Keyboard_Key_popupKeyboard
* @attr ref android.R.styleable#Keyboard_Key_popupCharacters
* @attr ref android.R.styleable#Keyboard_Key_keyOutputText
* @attr ref android.R.styleable#Keyboard_Key_keyEdgeFlags
*/
public static class Key {
/**
* 这个键的所有键值（code）都应该生成，第0个是总重要的。
* All the key codes (unicode or custom code) that this key could generate,
* zero'th being the most important.
*/
public int[] codes;
/** Label to display（每个键显示的Label） */
public CharSequence label;
/** Icon to display instead of a label. Icon takes precedence（优先） over a label */
public Drawable icon;
/** Preview version of the icon, for the preview popup（预览弹出框） */
public Drawable iconPreview;
/** Width of the key, not including the gap */
public int width;
/** Height of the key, not including the gap */
public int height;
/** The horizontal gap before this key */
public int gap;
/** Whether this key is sticky（粘滞键）, i.e., a toggle key */
public boolean sticky;
/** X coordinate of the key in the keyboard layout */
public int x;
/** Y coordinate of the key in the keyboard layout */
public int y;
/** The current pressed state of this key */
public boolean pressed;
/** If this is a sticky key, is it on? 如果是粘滞键，on应该是粘滞状态*/
public boolean on;
/** Text to output when pressed. This can be multiple characters, like ".com" */
public CharSequence text;
/** Popup characters */
public CharSequence popupCharacters;
/**
* 标志（标志寄存器）（bit mask 位掩码），明确的指出键的边界，以便检测出超出键边界的触摸事件。
* Flags that specify the anchoring to edges of the keyboard for detecting touch events
* that are just out of the boundary of the key. This is a bit mask of
* {@link Keyboard#EDGE_LEFT}, {@link Keyboard#EDGE_RIGHT}, {@link Keyboard#EDGE_TOP} and
* {@link Keyboard#EDGE_BOTTOM}.
*/
public int edgeFlags;//(0000 1111：表示在按键范围内)
/** Whether this is a modifier key（辅助按键，修改其他键的功能）, such as Shift or Alt */
public boolean modifier;
/** The keyboard that this key belongs to */
private Keyboard keyboard;
/**
* If this key pops up a mini keyboard, this is the resource id for the XML layout for that
* keyboard.
*/
public int popupResId;
/** Whether this key repeats（重复） itself when held down（按下） */
public boolean repeatable;
//定义各种KEY_STATE所包含的按键的基本状态
private final static int[] KEY_STATE_NORMAL_ON = {
android.R.attr.state_checkable,
android.R.attr.state_checked
};
private final static int[] KEY_STATE_PRESSED_ON = {
android.R.attr.state_pressed,
android.R.attr.state_checkable,
android.R.attr.state_checked
};
private final static int[] KEY_STATE_NORMAL_OFF = {
android.R.attr.state_checkable
};
private final static int[] KEY_STATE_PRESSED_OFF = {
android.R.attr.state_pressed,
android.R.attr.state_checkable
};
private final static int[] KEY_STATE_NORMAL = {
};
private final static int[] KEY_STATE_PRESSED = {
android.R.attr.state_pressed
};
/** Create an empty key with no attributes. */
public Key(Row parent) {
keyboard = parent.parent;
height = parent.defaultHeight;
width = parent.defaultWidth;
gap = parent.defaultHorizontalGap;
edgeFlags = parent.rowEdgeFlags;
}
/** Create a key with the given top-left（左上角） coordinate and extract（获取；提取；提拔）
* its attributes from the XML parser.
* @param res resources associated with the caller's context（与调用者的Context相关的资源）
* @param parent the row that this key belongs to. The row must already be attached to（联在一起）
* a {@link Keyboard}.（必须是在键盘中定义了的行）
* @param x the x coordinate of the top-left
* @param y the y coordinate of the top-left
* @param parser the XML parser containing the attributes for this key
*/
public Key(Resources res, Row parent, int x, int y, XmlResourceParser parser) {
this(parent);
this.x = x;
this.y = y;
TypedArray a = res.obtainAttributes(Xml.asAttributeSet(parser),
com.android.internal.R.styleable.Keyboard);
width = getDimensionOrFraction(a,
com.android.internal.R.styleable.Keyboard_keyWidth,
keyboard.mDisplayWidth, parent.defaultWidth);
height = getDimensionOrFraction(a,
com.android.internal.R.styleable.Keyboard_keyHeight,
keyboard.mDisplayHeight, parent.defaultHeight);
gap = getDimensionOrFraction(a,
com.android.internal.R.styleable.Keyboard_horizontalGap,
keyboard.mDisplayWidth, parent.defaultHorizontalGap);
a.recycle();
a = res.obtainAttributes(Xml.asAttributeSet(parser),
com.android.internal.R.styleable.Keyboard_Key);
this.x += gap;
TypedValue codesValue = new TypedValue();//键的code的类型
a.getValue(com.android.internal.R.styleable.Keyboard_Key_codes,
codesValue);//Returns true if the value was retrieved, else false.
if (codesValue.type == TypedValue.TYPE_INT_DEC || codesValue.type == TypedValue.TYPE_INT_HEX)
{
codes = new int[] { codesValue.data };
}
else if (codesValue.type == TypedValue.TYPE_STRING)
{
codes = parseCSV(codesValue.string.toString());
}
iconPreview = a.getDrawable(com.android.internal.R.styleable.Keyboard_Key_iconPreview);
if (iconPreview != null) {
iconPreview.setBounds(0, 0, iconPreview.getIntrinsicWidth(),
iconPreview.getIntrinsicHeight());//Return the intrinsic height of the
//underlying drawable object. Returns -1 if it has no intrinsic height, such as with a solid color.
}
popupCharacters = a.getText(
com.android.internal.R.styleable.Keyboard_Key_popupCharacters);
popupResId = a.getResourceId(
com.android.internal.R.styleable.Keyboard_Key_popupKeyboard, 0);
repeatable = a.getBoolean(
com.android.internal.R.styleable.Keyboard_Key_isRepeatable, false);
modifier = a.getBoolean(
com.android.internal.R.styleable.Keyboard_Key_isModifier, false);
sticky = a.getBoolean(
com.android.internal.R.styleable.Keyboard_Key_isSticky, false);
edgeFlags = a.getInt(com.android.internal.R.styleable.Keyboard_Key_keyEdgeFlags, 0);//Return attribute int value, or defValue if not defined.
edgeFlags |= parent.rowEdgeFlags;//a|=b等价于a=a|b
icon = a.getDrawable(
com.android.internal.R.styleable.Keyboard_Key_keyIcon);
if (icon != null) {
icon.setBounds(0, 0, icon.getIntrinsicWidth(), icon.getIntrinsicHeight());
}
label = a.getText(com.android.internal.R.styleable.Keyboard_Key_keyLabel);//CharSequence holding string data. May be styled. Returns null if the attribute is not defined.
text = a.getText(com.android.internal.R.styleable.Keyboard_Key_keyOutputText);
if (codes == null && !TextUtils.isEmpty(label)) {//Returns true if the string(label) is null or 0-length.
codes = new int[] { label.charAt(0) };//Returns the character at the specified index, with the first character having index zero.
}
a.recycle();
}
/**
* Informs the key that it has been pressed, in case it needs to change its appearance or
* state.
* @see #onReleased(boolean)
*/
public void onPressed() {
pressed = !pressed;
}
/**
* Changes the pressed state of the key. If it is a sticky key, it will also change the
* toggled state of the key if the finger was release inside.
* @param inside whether the finger was released inside the key
* @see #onPressed()
*/
public void onReleased(boolean inside) {
pressed = !pressed;//释放，非按下状态
if (sticky) {
on = !on;//（粘滞键）弹起状态(!on)
}
}
**//解析CSV,暂时没看懂。**
int[] parseCSV(String value) {
int count = 0;
int lastIndex = 0;
if (value.length() > 0) {
count++;
/**
* 方法：int java.lang.String.indexOf(String subString, int start)
* 源码：附在本文的最后面（附码1）
* 说明：Searches in this string(value) for the index of the specified string.
* The search for the string starts at the specified offset and moves
* towards the end of this string.
* 这里就是在value中，从第lastIndex + 1字符开始，向后查找“，”，查到一个count++。
* value.indexOf(",", lastIndex + 1)在查找结束的时候，返回-1。
* 最终的count = ","的个数 + 1.
*/
while ((lastIndex = value.indexOf(",", lastIndex + 1)) > 0) {
count++;
}
}
int[] values = new int[count];
count = 0;
//Constructs a new StringTokenizer(分词器) for the parameter string（字符串参数：value） using the specified delimiters（分隔符：","）.
StringTokenizer st = new StringTokenizer(value, ",");
while (st.hasMoreTokens()) {//Returns true if unprocessed tokens remain.
try {
//st.nextToken(): Returns the next token in the string as a String.
//Integer.parseInt(st.nextToken()): Parses the specified string as a signed decimal integer(有符十进制整数) value. The ASCII character \u002d ('-') is recognized as the minus sign.
values[count++] = Integer.parseInt(st.nextToken());
} catch (NumberFormatException nfe) {
Log.e(TAG, "Error parsing keycodes " + value);
}
}
return values;
}
/**
* Detects if a point falls inside this key.
* @param x the x-coordinate of the point
* @param y the y-coordinate of the point
* @return whether or not the point falls inside the key. If the key is attached to an edge,
* it will assume that all points between the key and the edge are considered to be inside
* the key.
*/
public boolean isInside(int x, int y) {
boolean leftEdge = (edgeFlags & EDGE_LEFT) > 0;
boolean rightEdge = (edgeFlags & EDGE_RIGHT) > 0;
boolean topEdge = (edgeFlags & EDGE_TOP) > 0;
boolean bottomEdge = (edgeFlags & EDGE_BOTTOM) > 0;
if ((x >= this.x || (leftEdge && x <= this.x + this.width))
&& (x < this.x + this.width || (rightEdge && x >= this.x))
&& (y >= this.y || (topEdge && y <= this.y + this.height))
&& (y < this.y + this.height || (bottomEdge && y >= this.y))) {
return true;
} else {
return false;
}
}
/**
* Returns the square of the distance（距离的平方） between the center of the key
* and the given point.
* @param x the x-coordinate of the point
* @param y the y-coordinate of the point
* @return the square of the distance of the point from the center of the key
*/
public int squaredDistanceFrom(int x, int y) {
int xDist = this.x + width / 2 - x;
int yDist = this.y + height / 2 - y;
return xDist * xDist + yDist * yDist;
}
/**
* Returns the drawable state for the key, based on the current state and type of the key.
* @return the drawable state of the key.
* @see android.graphics.drawable.StateListDrawable#setState(int[])
*/
public int[] getCurrentDrawableState() {
int[] states = KEY_STATE_NORMAL;
if (on) {//粘滞键处于粘滞状态
if (pressed) {
states = KEY_STATE_PRESSED_ON;
} else {
states = KEY_STATE_NORMAL_ON;
}
} else {
if (sticky) {
if (pressed) {
states = KEY_STATE_PRESSED_OFF;
} else {
states = KEY_STATE_NORMAL_OFF;
}
} else {
if (pressed) {
states = KEY_STATE_PRESSED;
}
}
}
return states;
}
}
/**
* Creates a keyboard from the given xml key layout file.
* @param context the application or service context
* @param xmlLayoutResId the resource file that contains the keyboard layout and keys.
*/
public Keyboard(Context context, int xmlLayoutResId) {
this(context, xmlLayoutResId, 0);
}
/**
* Creates a keyboard from the given xml key layout file. Weeds out rows
* that have a keyboard mode defined but don't match the specified mode.
* @param context the application or service context
* @param xmlLayoutResId the resource file that contains the keyboard layout and keys.
* @param modeId keyboard mode identifier
* @param width sets width of keyboard
* @param height sets height of keyboard
*/
public Keyboard(Context context, int xmlLayoutResId, int modeId, int width, int height) {
mDisplayWidth = width;
mDisplayHeight = height;
mDefaultHorizontalGap = 0;
mDefaultWidth = mDisplayWidth / 10;
mDefaultVerticalGap = 0;
mDefaultHeight = mDefaultWidth;
mKeys = new ArrayList<Key>();
mModifierKeys = new ArrayList<Key>();
mKeyboardMode = modeId;
loadKeyboard(context, context.getResources().getXml(xmlLayoutResId));
}
/**
* Creates a keyboard from the given xml key layout file. Weeds out rows
* that have a keyboard mode defined but don't match the specified mode.
* @param context the application or service context
* @param xmlLayoutResId the resource file that contains the keyboard layout and keys.
* @param modeId keyboard mode identifier
*/
public Keyboard(Context context, int xmlLayoutResId, int modeId) {
DisplayMetrics dm = context.getResources().getDisplayMetrics();
mDisplayWidth = dm.widthPixels;
mDisplayHeight = dm.heightPixels;
//Log.v(TAG, "keyboard's display metrics:" + dm);
mDefaultHorizontalGap = 0;
mDefaultWidth = mDisplayWidth / 10;
mDefaultVerticalGap = 0;
mDefaultHeight = mDefaultWidth;
mKeys = new ArrayList<Key>();
mModifierKeys = new ArrayList<Key>();
mKeyboardMode = modeId;
loadKeyboard(context, context.getResources().getXml(xmlLayoutResId));
}
/**
* <p>Creates a blank keyboard from the given resource file and
* populates（定位，安置） it with the specified characters in left-to-right, top-to-bottom fashion,
* using the specified number of columns.
* </p>
* <p>If the specified number of columns is -1, then the keyboard will fit as many keys as
* possible in each row.</p>
* @param context the application or service context
* @param layoutTemplateResId the layout template（模板） file, containing no keys.
* @param characters the list of characters（需要显示的字符） to display on the keyboard. One key will be created
* for each character.
* @param columns the number of columns of keys to display. If this number is greater than the
* number of keys that can fit in a row, it will be ignored. If this number is -1, the
* keyboard will fit as many keys as possible in each row.
*/
public Keyboard(Context context, int layoutTemplateResId,
CharSequence characters, int columns, int horizontalPadding) {
this(context, layoutTemplateResId);
int x = 0;
int y = 0;
int column = 0;
mTotalWidth = 0;
Row row = new Row(this);
row.defaultHeight = mDefaultHeight;
row.defaultWidth = mDefaultWidth;
row.defaultHorizontalGap = mDefaultHorizontalGap;
row.verticalGap = mDefaultVerticalGap;
row.rowEdgeFlags = EDGE_TOP | EDGE_BOTTOM;
final int maxColumns = columns == -1 ? Integer.MAX_VALUE : columns;
for (int i = 0; i < characters.length(); i++) {
char c = characters.charAt(i);
if (column >= maxColumns
|| x + mDefaultWidth + horizontalPadding > mDisplayWidth) {
x = 0;
y += mDefaultVerticalGap + mDefaultHeight;
column = 0;
}
final Key key = new Key(row);
key.x = x;
key.y = y;
key.label = String.valueOf(c);
key.codes = new int[] { c };
column++;
x += key.width + key.gap;
mKeys.add(key);
row.mKeys.add(key);
if (x > mTotalWidth) {
mTotalWidth = x;
}
}
mTotalHeight = y + mDefaultHeight;
rows.add(row);
}
final void resize(int newWidth, int newHeight) {
int numRows = rows.size();
for (int rowIndex = 0; rowIndex < numRows; ++rowIndex) {
Row row = rows.get(rowIndex);
int numKeys = row.mKeys.size();
int totalGap = 0;
int totalWidth = 0;
for (int keyIndex = 0; keyIndex < numKeys; ++keyIndex) {
Key key = row.mKeys.get(keyIndex);
if (keyIndex > 0) {
totalGap += key.gap;
}
totalWidth += key.width;
}
if (totalGap + totalWidth > newWidth) {
int x = 0;
float scaleFactor = (float)(newWidth - totalGap) / totalWidth;
for (int keyIndex = 0; keyIndex < numKeys; ++keyIndex) {
Key key = row.mKeys.get(keyIndex);
key.width *= scaleFactor;
key.x = x;
x += key.width + key.gap;
}
}
}
mTotalWidth = newWidth;
// TODO: This does not adjust the vertical placement according to the new size.
// The main problem in the previous code was horizontal placement/size, but we should
// also recalculate the vertical sizes/positions when we get this resize call.
}
public List<Key> getKeys() {
return mKeys;
}
public List<Key> getModifierKeys() {
return mModifierKeys;
}
protected int getHorizontalGap() {
return mDefaultHorizontalGap;
}
protected void setHorizontalGap(int gap) {
mDefaultHorizontalGap = gap;
}
protected int getVerticalGap() {
return mDefaultVerticalGap;
}
protected void setVerticalGap(int gap) {
mDefaultVerticalGap = gap;
}
protected int getKeyHeight() {
return mDefaultHeight;
}
protected void setKeyHeight(int height) {
mDefaultHeight = height;
}
protected int getKeyWidth() {
return mDefaultWidth;
}
protected void setKeyWidth(int width) {
mDefaultWidth = width;
}
/**
* Returns the total height of the keyboard
* @return the total height of the keyboard
*/
public int getHeight() {
return mTotalHeight;
}
public int getMinWidth() {
return mTotalWidth;
}
public boolean setShifted(boolean shiftState) {
for (Key shiftKey : mShiftKeys) {
if (shiftKey != null) {
shiftKey.on = shiftState;
}
}
if (mShifted != shiftState) {
mShifted = shiftState;
return true;
}
return false;
}
public boolean isShifted() {
return mShifted;
}
/**
* @hide
*/
public int[] getShiftKeyIndices() {
return mShiftKeyIndices;
}
public int getShiftKeyIndex() {
return mShiftKeyIndices[0];
}
private void computeNearestNeighbors() {
// Round-up so we don't have any pixels outside the grid
mCellWidth = (getMinWidth() + GRID_WIDTH - 1) / GRID_WIDTH;
mCellHeight = (getHeight() + GRID_HEIGHT - 1) / GRID_HEIGHT;
mGridNeighbors = new int[GRID_SIZE][];
int[] indices = new int[mKeys.size()];
final int gridWidth = GRID_WIDTH * mCellWidth;
final int gridHeight = GRID_HEIGHT * mCellHeight;
for (int x = 0; x < gridWidth; x += mCellWidth) {
for (int y = 0; y < gridHeight; y += mCellHeight) {
int count = 0;
for (int i = 0; i < mKeys.size(); i++) {
final Key key = mKeys.get(i);
if (key.squaredDistanceFrom(x, y) < mProximityThreshold ||
key.squaredDistanceFrom(x + mCellWidth - 1, y) < mProximityThreshold ||
key.squaredDistanceFrom(x + mCellWidth - 1, y + mCellHeight - 1)
< mProximityThreshold ||
key.squaredDistanceFrom(x, y + mCellHeight - 1) < mProximityThreshold) {
indices[count++] = i;
}
}
int [] cell = new int[count];
System.arraycopy(indices, 0, cell, 0, count);
mGridNeighbors[(y / mCellHeight) * GRID_WIDTH + (x / mCellWidth)] = cell;
}
}
}
/**
* Returns the indices of the keys that are closest to the given point.
* @param x the x-coordinate of the point
* @param y the y-coordinate of the point
* @return the array of integer indices for the nearest keys to the given point. If the given
* point is out of range, then an array of size zero is returned.
*/
public int[] getNearestKeys(int x, int y) {
if (mGridNeighbors == null) computeNearestNeighbors();
if (x >= 0 && x < getMinWidth() && y >= 0 && y < getHeight()) {
int index = (y / mCellHeight) * GRID_WIDTH + (x / mCellWidth);
if (index < GRID_SIZE) {
return mGridNeighbors[index];
}
}
return new int[0];
}
protected Row createRowFromXml(Resources res, XmlResourceParser parser) {
return new Row(res, this, parser);
}
protected Key createKeyFromXml(Resources res, Row parent, int x, int y,
XmlResourceParser parser) {
return new Key(res, parent, x, y, parser);
}
private void loadKeyboard(Context context, XmlResourceParser parser) {
boolean inKey = false;
boolean inRow = false;
boolean leftMostKey = false;
int row = 0;
int x = 0;
int y = 0;
Key key = null;
Row currentRow = null;
Resources res = context.getResources();
boolean skipRow = false;
try {
int event;
while ((event = parser.next()) != XmlResourceParser.END_DOCUMENT) {
if (event == XmlResourceParser.START_TAG) {
String tag = parser.getName();
if (TAG_ROW.equals(tag)) {
inRow = true;
x = 0;
currentRow = createRowFromXml(res, parser);
rows.add(currentRow);
skipRow = currentRow.mode != 0 && currentRow.mode != mKeyboardMode;
if (skipRow) {
skipToEndOfRow(parser);
inRow = false;
}
} else if (TAG_KEY.equals(tag)) {
inKey = true;
key = createKeyFromXml(res, currentRow, x, y, parser);
mKeys.add(key);
if (key.codes[0] == KEYCODE_SHIFT) {
// Find available shift key slot（位置） and put this shift key in it
for (int i = 0; i < mShiftKeys.length; i++) {
if (mShiftKeys[i] == null) {
mShiftKeys[i] = key;
mShiftKeyIndices[i] = mKeys.size()-1;
break;
}
}
mModifierKeys.add(key);
} else if (key.codes[0] == KEYCODE_ALT) {
mModifierKeys.add(key);
}
currentRow.mKeys.add(key);
} else if (TAG_KEYBOARD.equals(tag)) {
parseKeyboardAttributes(res, parser);
}
} else if (event == XmlResourceParser.END_TAG) {
if (inKey) {
inKey = false;
x += key.gap + key.width;
if (x > mTotalWidth) {
mTotalWidth = x;
}
} else if (inRow) {
inRow = false;
y += currentRow.verticalGap;
y += currentRow.defaultHeight;
row++;
} else {
// TODO: error or extend?
}
}
}
} catch (Exception e) {
Log.e(TAG, "Parse error:" + e);
e.printStackTrace();
}
mTotalHeight = y - mDefaultVerticalGap;
}
private void skipToEndOfRow(XmlResourceParser parser)
throws XmlPullParserException, IOException {
int event;
while ((event = parser.next()) != XmlResourceParser.END_DOCUMENT) {
if (event == XmlResourceParser.END_TAG
&& parser.getName().equals(TAG_ROW)) {
break;
}
}
}
private void parseKeyboardAttributes(Resources res, XmlResourceParser parser) {
TypedArray a = res.obtainAttributes(Xml.asAttributeSet(parser),
com.android.internal.R.styleable.Keyboard);
mDefaultWidth = getDimensionOrFraction(a,
com.android.internal.R.styleable.Keyboard_keyWidth,
mDisplayWidth, mDisplayWidth / 10);
mDefaultHeight = getDimensionOrFraction(a,
com.android.internal.R.styleable.Keyboard_keyHeight,
mDisplayHeight, 50);
mDefaultHorizontalGap = getDimensionOrFraction(a,
com.android.internal.R.styleable.Keyboard_horizontalGap,
mDisplayWidth, 0);
mDefaultVerticalGap = getDimensionOrFraction(a,
com.android.internal.R.styleable.Keyboard_verticalGap,
mDisplayHeight, 0);
mProximityThreshold = (int) (mDefaultWidth * SEARCH_DISTANCE);
mProximityThreshold = mProximityThreshold * mProximityThreshold; // Square it for comparison
a.recycle();
}
static int getDimensionOrFraction(TypedArray a, int index, int base, int defValue) {
TypedValue value = a.peekValue(index);
if (value == null) return defValue;
if (value.type == TypedValue.TYPE_DIMENSION) {
return a.getDimensionPixelOffset(index, defValue);
} else if (value.type == TypedValue.TYPE_FRACTION) {
// Round it to avoid values like 47.9999 from getting truncated
return Math.round(a.getFraction(index, base, base, defValue));
}
return defValue;
}
}
附码1：package java.lang.String.indexOf(String subString, int start)
/**
* Searches in this string for the index of the specified string. The search
* for the string starts at the specified offset and moves towards the end
* of this string.
*
* @param subString
* the string to find.
* @param start
* the starting offset.
* @return the index of the first character of the specified string in this
* string, -1 if the specified string is not a substring.
* @throws NullPointerException
* if {@code subString} is {@code null}.
*/
public int indexOf(String subString, int start) {
if (start < 0) {
start = 0;
}
int subCount = subString.count;
int _count = count;
if (subCount > 0) {
if (subCount + start > _count) {
return -1;
}
char[] target = subString.value;
int subOffset = subString.offset;
char firstChar = target[subOffset];
int end = subOffset + subCount;
while (true) {
int i = indexOf(firstChar, start);
if (i == -1 || subCount + i > _count) {
return -1; // handles subCount > count || start >= count
}
int o1 = offset + i, o2 = subOffset;
char[] _value = value;
while (++o2 < end && _value[++o1] == target[o2]) {
// Intentionally empty
}
if (o2 == end) {
return i;
}
start = i + 1;
}
}
return start < _count ? start : _count;
}
附码2： package java.util;
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 java.util;
/**
* Breaks a string into tokens; new code should probably use {@link String#split}.
*
* <blockquote>
* <pre>
* // Legacy code:
* StringTokenizer st = new StringTokenizer("a:b:c", ":");
* while (st.hasMoreTokens()) {
* System.err.println(st.nextToken());
* }
*
* // New code:
* for (String token : "a:b:c".split(":")) {
* System.err.println(token);
* }
* </pre>
* </blockquote>
*
* @since 1.0
*/
public class StringTokenizer implements Enumeration<Object> {
private String string;
private String delimiters;
private boolean returnDelimiters;
private int position;
/**
* Constructs a new {@code StringTokenizer} for the parameter string using
* whitespace as the delimiter. The {@code returnDelimiters} flag is set to
* {@code false}.
*
* @param string
* the string to be tokenized.
*/
public StringTokenizer(String string) {
this(string, " \t\n\r\f", false);
}
/**
* Constructs a new {@code StringTokenizer} for the parameter string using
* the specified delimiters. The {@code returnDelimiters} flag is set to
* {@code false}. If {@code delimiters} is {@code null}, this constructor
* doesn't throw an {@code Exception}, but later calls to some methods might
* throw a {@code NullPointerException}.
*
* @param string
* the string to be tokenized.
* @param delimiters
* the delimiters to use.（分隔符们：分隔符组成的字符串，例如：" \t\n\r\f"）
*/
public StringTokenizer(String string, String delimiters) {
this(string, delimiters, false);//false:分隔符本身不放入tokens中
}
/**
* Constructs a new {@code StringTokenizer} for the parameter string using
* the specified delimiters, returning the delimiters as tokens if the
* parameter {@code returnDelimiters} is {@code true}. If {@code delimiters}
* is null this constructor doesn't throw an {@code Exception}, but later
* calls to some methods might throw a {@code NullPointerException}.
*
* @param string
* the string to be tokenized.
* @param delimiters
* the delimiters to use.
* @param returnDelimiters
* {@code true} to return each delimiter as a token.
*/
public StringTokenizer(String string, String delimiters,
boolean returnDelimiters) {
if (string != null) {
this.string = string;
this.delimiters = delimiters;
this.returnDelimiters = returnDelimiters;
this.position = 0;
} else
throw new NullPointerException();
}
/**
* Returns the number of unprocessed tokens remaining in the string.
*
* @return number of tokens that can be retreived before an {@code
* Exception} will result from a call to {@code nextToken()}.
*/
public int countTokens() {
int count = 0;
boolean inToken = false;
for (int i = position, length = string.length(); i < length; i++) {
if (delimiters.indexOf(string.charAt(i), 0) >= 0) {
if (returnDelimiters)
count++;
if (inToken) {
count++;
inToken = false;
}
} else {
inToken = true;
}
}
if (inToken)
count++;
return count;
}
/**
* Returns {@code true} if unprocessed tokens remain. This method is
* implemented in order to satisfy the {@code Enumeration} interface.
*
* @return {@code true} if unprocessed tokens remain.
*/
public boolean hasMoreElements() {
return hasMoreTokens();
}
/**
* Returns {@code true} if unprocessed tokens remain.
*
* @return {@code true} if unprocessed tokens remain.
*/
public boolean hasMoreTokens() {
if (delimiters == null) {
throw new NullPointerException();
}
int length = string.length();
if (position < length) {
if (returnDelimiters)
return true; // there is at least one character and even if
// it is a delimiter it is a token
// otherwise find a character which is not a delimiter
for (int i = position; i < length; i++)
if (delimiters.indexOf(string.charAt(i), 0) == -1)
return true;
}
return false;
}
/**
* Returns the next token in the string as an {@code Object}. This method is
* implemented in order to satisfy the {@code Enumeration} interface.
*
* @return next token in the string as an {@code Object}
* @throws NoSuchElementException
* if no tokens remain.
*/
public Object nextElement() {
return nextToken();
}
/**
* Returns the next token in the string as a {@code String}.
*
* @return next token in the string as a {@code String}.
* @throws NoSuchElementException
* if no tokens remain.
*/
public String nextToken() {
if (delimiters == null) {
throw new NullPointerException();
}
int i = position;
int length = string.length();
if (i < length) {
if (returnDelimiters) {
if (delimiters.indexOf(string.charAt(position), 0) >= 0)
return String.valueOf(string.charAt(position++));
for (position++; position < length; position++)
if (delimiters.indexOf(string.charAt(position), 0) >= 0)
return string.substring(i, position);
return string.substring(i);
}
while (i < length && delimiters.indexOf(string.charAt(i), 0) >= 0)
i++;
position = i;
if (i < length) {
for (position++; position < length; position++)
if (delimiters.indexOf(string.charAt(position), 0) >= 0)
return string.substring(i, position);
return string.substring(i);
}
}
throw new NoSuchElementException();
}
/**
* Returns the next token in the string as a {@code String}. The delimiters
* used are changed to the specified delimiters.
*
* @param delims
* the new delimiters to use.
* @return next token in the string as a {@code String}.
* @throws NoSuchElementException
* if no tokens remain.
*/
public String nextToken(String delims) {
this.delimiters = delims;
return nextToken();
}
}
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