Java tutorial
/* * Copyright (C) 2013 The Android Open Source Project * * 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 app.android.datetimepicker.date; import android.content.Context; import android.content.res.Resources; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Paint.Align; import android.graphics.Paint.Style; import android.graphics.Rect; import android.graphics.Typeface; import android.os.Bundle; import android.support.v4.view.ViewCompat; import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat; import android.support.v4.widget.ExploreByTouchHelper; import android.text.format.DateFormat; import android.text.format.DateUtils; import android.text.format.Time; import android.view.MotionEvent; import android.view.View; import android.view.accessibility.AccessibilityEvent; import android.view.accessibility.AccessibilityNodeInfo; import com.android.datetimepicker.R; import app.android.datetimepicker.Utils; import java.security.InvalidParameterException; import java.util.Calendar; import java.util.Formatter; import java.util.HashMap; import java.util.List; import java.util.Locale; /** * A calendar-like view displaying a specified month and the appropriate selectable day numbers * within the specified month. */ public class SimpleMonthView extends View { private static final String TAG = "SimpleMonthView"; /** * These params can be passed into the view to control how it appears. * {@link #VIEW_PARAMS_WEEK} is the only required field, though the default * values are unlikely to fit most layouts correctly. */ /** * This sets the height of this week in pixels */ public static final String VIEW_PARAMS_HEIGHT = "height"; /** * This specifies the position (or weeks since the epoch) of this week, * calculated using {@link Utils#getWeeksSinceEpochFromJulianDay} */ public static final String VIEW_PARAMS_MONTH = "month"; /** * This specifies the position (or weeks since the epoch) of this week, * calculated using {@link Utils#getWeeksSinceEpochFromJulianDay} */ public static final String VIEW_PARAMS_YEAR = "year"; /** * This sets one of the days in this view as selected {@link Time#SUNDAY} * through {@link Time#SATURDAY}. */ public static final String VIEW_PARAMS_SELECTED_DAY = "selected_day"; /** * Which day the week should start on. {@link Time#SUNDAY} through * {@link Time#SATURDAY}. */ public static final String VIEW_PARAMS_WEEK_START = "week_start"; /** * How many days to display at a time. Days will be displayed starting with * {@link #mWeekStart}. */ public static final String VIEW_PARAMS_NUM_DAYS = "num_days"; /** * Which month is currently in focus, as defined by {@link Time#month} * [0-11]. */ public static final String VIEW_PARAMS_FOCUS_MONTH = "focus_month"; /** * If this month should display week numbers. false if 0, true otherwise. */ public static final String VIEW_PARAMS_SHOW_WK_NUM = "show_wk_num"; protected static int DEFAULT_HEIGHT = 32; protected static int MIN_HEIGHT = 10; protected static final int DEFAULT_SELECTED_DAY = -1; protected static final int DEFAULT_WEEK_START = Calendar.SUNDAY; protected static final int DEFAULT_NUM_DAYS = 7; protected static final int DEFAULT_SHOW_WK_NUM = 0; protected static final int DEFAULT_FOCUS_MONTH = -1; protected static final int DEFAULT_NUM_ROWS = 6; protected static final int MAX_NUM_ROWS = 6; private static final int SELECTED_CIRCLE_ALPHA = 60; protected static int DAY_SEPARATOR_WIDTH = 1; protected static int MINI_DAY_NUMBER_TEXT_SIZE; protected static int MONTH_LABEL_TEXT_SIZE; protected static int MONTH_DAY_LABEL_TEXT_SIZE; protected static int MONTH_HEADER_SIZE; protected static int DAY_SELECTED_CIRCLE_SIZE; // used for scaling to the device density protected static float mScale = 0; // affects the padding on the sides of this view protected int mPadding = 0; private String mDayOfWeekTypeface; private String mMonthTitleTypeface; protected Paint mMonthNumPaint; protected Paint mMonthTitlePaint; protected Paint mMonthTitleBGPaint; protected Paint mSelectedCirclePaint; protected Paint mMonthDayLabelPaint; private final Formatter mFormatter; private final StringBuilder mStringBuilder; // The Julian day of the first day displayed by this item protected int mFirstJulianDay = -1; // The month of the first day in this week protected int mFirstMonth = -1; // The month of the last day in this week protected int mLastMonth = -1; protected int mMonth; protected int mYear; // Quick reference to the width of this view, matches parent protected int mWidth; // The height this view should draw at in pixels, set by height param protected int mRowHeight = DEFAULT_HEIGHT; // If this view contains the today protected boolean mHasToday = false; // Which day is selected [0-6] or -1 if no day is selected protected int mSelectedDay = -1; // Which day is today [0-6] or -1 if no day is today protected int mToday = DEFAULT_SELECTED_DAY; // Which day of the week to start on [0-6] protected int mWeekStart = DEFAULT_WEEK_START; // How many days to display protected int mNumDays = DEFAULT_NUM_DAYS; // The number of days + a spot for week number if it is displayed protected int mNumCells = mNumDays; // The left edge of the selected day protected int mSelectedLeft = -1; // The right edge of the selected day protected int mSelectedRight = -1; private final Calendar mCalendar; private final Calendar mDayLabelCalendar; private final MonthViewTouchHelper mTouchHelper; private int mNumRows = DEFAULT_NUM_ROWS; // Optional listener for handling day click actions private OnDayClickListener mOnDayClickListener; // Whether to prevent setting the accessibility delegate private boolean mLockAccessibilityDelegate; protected int mDayTextColor; protected int mTodayNumberColor; protected int mMonthTitleColor; protected int mMonthTitleBGColor; public SimpleMonthView(Context context) { super(context); Resources res = context.getResources(); mDayLabelCalendar = Calendar.getInstance(); mCalendar = Calendar.getInstance(); mDayOfWeekTypeface = res.getString(R.string.day_of_week_label_typeface); mMonthTitleTypeface = res.getString(R.string.sans_serif); mDayTextColor = res.getColor(R.color.date_picker_text_normal); mTodayNumberColor = res.getColor(R.color.blue); mMonthTitleColor = res.getColor(R.color.white); mMonthTitleBGColor = res.getColor(R.color.circle_background); mStringBuilder = new StringBuilder(50); mFormatter = new Formatter(mStringBuilder, Locale.getDefault()); MINI_DAY_NUMBER_TEXT_SIZE = res.getDimensionPixelSize(R.dimen.day_number_size); MONTH_LABEL_TEXT_SIZE = res.getDimensionPixelSize(R.dimen.month_label_size); MONTH_DAY_LABEL_TEXT_SIZE = res.getDimensionPixelSize(R.dimen.month_day_label_text_size); MONTH_HEADER_SIZE = res.getDimensionPixelOffset(R.dimen.month_list_item_header_height); DAY_SELECTED_CIRCLE_SIZE = res.getDimensionPixelSize(R.dimen.day_number_select_circle_radius); mRowHeight = (res.getDimensionPixelOffset(R.dimen.date_picker_view_animator_height) - MONTH_HEADER_SIZE) / MAX_NUM_ROWS; // Set up accessibility components. mTouchHelper = new MonthViewTouchHelper(this); ViewCompat.setAccessibilityDelegate(this, mTouchHelper); ViewCompat.setImportantForAccessibility(this, ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_YES); mLockAccessibilityDelegate = true; // Sets up any standard paints that will be used initView(); } @Override public void setAccessibilityDelegate(AccessibilityDelegate delegate) { // Workaround for a JB MR1 issue where accessibility delegates on // top-level ListView items are overwritten. if (!mLockAccessibilityDelegate) { super.setAccessibilityDelegate(delegate); } } public void setOnDayClickListener(OnDayClickListener listener) { mOnDayClickListener = listener; } @Override public boolean dispatchHoverEvent(MotionEvent event) { // First right-of-refusal goes the touch exploration helper. if (mTouchHelper.dispatchHoverEvent(event)) { return true; } return super.dispatchHoverEvent(event); } @Override public boolean onTouchEvent(MotionEvent event) { switch (event.getAction()) { case MotionEvent.ACTION_UP: final int day = getDayFromLocation(event.getX(), event.getY()); if (day >= 0) { onDayClick(day); } break; } return true; } /** * Sets up the text and style properties for painting. Override this if you * want to use a different paint. */ protected void initView() { mMonthTitlePaint = new Paint(); mMonthTitlePaint.setFakeBoldText(true); mMonthTitlePaint.setAntiAlias(true); mMonthTitlePaint.setTextSize(MONTH_LABEL_TEXT_SIZE); mMonthTitlePaint.setTypeface(Typeface.create(mMonthTitleTypeface, Typeface.BOLD)); mMonthTitlePaint.setColor(mDayTextColor); mMonthTitlePaint.setTextAlign(Align.CENTER); mMonthTitlePaint.setStyle(Style.FILL); mMonthTitleBGPaint = new Paint(); mMonthTitleBGPaint.setFakeBoldText(true); mMonthTitleBGPaint.setAntiAlias(true); mMonthTitleBGPaint.setColor(mMonthTitleBGColor); mMonthTitleBGPaint.setTextAlign(Align.CENTER); mMonthTitleBGPaint.setStyle(Style.FILL); mSelectedCirclePaint = new Paint(); mSelectedCirclePaint.setFakeBoldText(true); mSelectedCirclePaint.setAntiAlias(true); mSelectedCirclePaint.setColor(mTodayNumberColor); mSelectedCirclePaint.setTextAlign(Align.CENTER); mSelectedCirclePaint.setStyle(Style.FILL); mSelectedCirclePaint.setAlpha(SELECTED_CIRCLE_ALPHA); mMonthDayLabelPaint = new Paint(); mMonthDayLabelPaint.setAntiAlias(true); mMonthDayLabelPaint.setTextSize(MONTH_DAY_LABEL_TEXT_SIZE); mMonthDayLabelPaint.setColor(mDayTextColor); mMonthDayLabelPaint.setTypeface(Typeface.create(mDayOfWeekTypeface, Typeface.NORMAL)); mMonthDayLabelPaint.setStyle(Style.FILL); mMonthDayLabelPaint.setTextAlign(Align.CENTER); mMonthDayLabelPaint.setFakeBoldText(true); mMonthNumPaint = new Paint(); mMonthNumPaint.setAntiAlias(true); mMonthNumPaint.setTextSize(MINI_DAY_NUMBER_TEXT_SIZE); mMonthNumPaint.setStyle(Style.FILL); mMonthNumPaint.setTextAlign(Align.CENTER); mMonthNumPaint.setFakeBoldText(false); } @Override protected void onDraw(Canvas canvas) { drawMonthTitle(canvas); drawMonthDayLabels(canvas); drawMonthNums(canvas); } private int mDayOfWeekStart = 0; /** * Sets all the parameters for displaying this week. The only required * parameter is the week number. Other parameters have a default value and * will only update if a new value is included, except for focus month, * which will always default to no focus month if no value is passed in. See * {@link #VIEW_PARAMS_HEIGHT} for more info on parameters. * * @param params A map of the new parameters, see * {@link #VIEW_PARAMS_HEIGHT} */ public void setMonthParams(HashMap<String, Integer> params) { if (!params.containsKey(VIEW_PARAMS_MONTH) && !params.containsKey(VIEW_PARAMS_YEAR)) { throw new InvalidParameterException("You must specify the month and year for this view"); } setTag(params); // We keep the current value for any params not present if (params.containsKey(VIEW_PARAMS_HEIGHT)) { mRowHeight = params.get(VIEW_PARAMS_HEIGHT); if (mRowHeight < MIN_HEIGHT) { mRowHeight = MIN_HEIGHT; } } if (params.containsKey(VIEW_PARAMS_SELECTED_DAY)) { mSelectedDay = params.get(VIEW_PARAMS_SELECTED_DAY); } // Allocate space for caching the day numbers and focus values mMonth = params.get(VIEW_PARAMS_MONTH); mYear = params.get(VIEW_PARAMS_YEAR); // Figure out what day today is final Time today = new Time(Time.getCurrentTimezone()); today.setToNow(); mHasToday = false; mToday = -1; mCalendar.set(Calendar.MONTH, mMonth); mCalendar.set(Calendar.YEAR, mYear); mCalendar.set(Calendar.DAY_OF_MONTH, 1); mDayOfWeekStart = mCalendar.get(Calendar.DAY_OF_WEEK); if (params.containsKey(VIEW_PARAMS_WEEK_START)) { mWeekStart = params.get(VIEW_PARAMS_WEEK_START); } else { mWeekStart = mCalendar.getFirstDayOfWeek(); } mNumCells = Utils.getDaysInMonth(mMonth, mYear); for (int i = 0; i < mNumCells; i++) { final int day = i + 1; if (sameDay(day, today)) { mHasToday = true; mToday = day; } } mNumRows = calculateNumRows(); // Invalidate cached accessibility information. mTouchHelper.invalidateRoot(); } public void reuse() { mNumRows = DEFAULT_NUM_ROWS; requestLayout(); } private int calculateNumRows() { int offset = findDayOffset(); int dividend = (offset + mNumCells) / mNumDays; int remainder = (offset + mNumCells) % mNumDays; return (dividend + (remainder > 0 ? 1 : 0)); } private boolean sameDay(int day, Time today) { return mYear == today.year && mMonth == today.month && day == today.monthDay; } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { setMeasuredDimension(MeasureSpec.getSize(widthMeasureSpec), mRowHeight * mNumRows + MONTH_HEADER_SIZE); } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { mWidth = w; // Invalidate cached accessibility information. mTouchHelper.invalidateRoot(); } private String getMonthAndYearString() { int flags = DateUtils.FORMAT_SHOW_DATE | DateUtils.FORMAT_SHOW_YEAR | DateUtils.FORMAT_NO_MONTH_DAY; mStringBuilder.setLength(0); long millis = mCalendar.getTimeInMillis(); return DateUtils.formatDateRange(getContext(), mFormatter, millis, millis, flags, Time.getCurrentTimezone()) .toString(); } private void drawMonthTitle(Canvas canvas) { int x = (mWidth + 2 * mPadding) / 2; int y = (MONTH_HEADER_SIZE - MONTH_DAY_LABEL_TEXT_SIZE) / 2 + (MONTH_LABEL_TEXT_SIZE / 3); canvas.drawText(getMonthAndYearString(), x, y, mMonthTitlePaint); } private void drawMonthDayLabels(Canvas canvas) { int y = MONTH_HEADER_SIZE - (MONTH_DAY_LABEL_TEXT_SIZE / 2); int dayWidthHalf = (mWidth - mPadding * 2) / (mNumDays * 2); for (int i = 0; i < mNumDays; i++) { int calendarDay = (i + mWeekStart) % mNumDays; int x = (2 * i + 1) * dayWidthHalf + mPadding; mDayLabelCalendar.set(Calendar.DAY_OF_WEEK, calendarDay); canvas.drawText( mDayLabelCalendar.getDisplayName(Calendar.DAY_OF_WEEK, Calendar.SHORT, Locale.getDefault()) .toUpperCase(Locale.getDefault()), x, y, mMonthDayLabelPaint); } } /** * Draws the week and month day numbers for this week. Override this method * if you need different placement. * * @param canvas The canvas to draw on */ protected void drawMonthNums(Canvas canvas) { int y = (((mRowHeight + MINI_DAY_NUMBER_TEXT_SIZE) / 2) - DAY_SEPARATOR_WIDTH) + MONTH_HEADER_SIZE; int dayWidthHalf = (mWidth - mPadding * 2) / (mNumDays * 2); int j = findDayOffset(); for (int dayNumber = 1; dayNumber <= mNumCells; dayNumber++) { int x = (2 * j + 1) * dayWidthHalf + mPadding; if (mSelectedDay == dayNumber) { canvas.drawCircle(x, y - (MINI_DAY_NUMBER_TEXT_SIZE / 3), DAY_SELECTED_CIRCLE_SIZE, mSelectedCirclePaint); } if (mHasToday && mToday == dayNumber) { mMonthNumPaint.setColor(mTodayNumberColor); } else { mMonthNumPaint.setColor(mDayTextColor); } canvas.drawText(String.format("%d", dayNumber), x, y, mMonthNumPaint); j++; if (j == mNumDays) { j = 0; y += mRowHeight; } } } private int findDayOffset() { return (mDayOfWeekStart < mWeekStart ? (mDayOfWeekStart + mNumDays) : mDayOfWeekStart) - mWeekStart; } /** * Calculates the day that the given x position is in, accounting for week * number. Returns the day or -1 if the position wasn't in a day. * * @param x The x position of the touch event * @return The day number, or -1 if the position wasn't in a day */ public int getDayFromLocation(float x, float y) { int dayStart = mPadding; if (x < dayStart || x > mWidth - mPadding) { return -1; } // Selection is (x - start) / (pixels/day) == (x -s) * day / pixels int row = (int) (y - MONTH_HEADER_SIZE) / mRowHeight; int column = (int) ((x - dayStart) * mNumDays / (mWidth - dayStart - mPadding)); int day = column - findDayOffset() + 1; day += row * mNumDays; if (day < 1 || day > mNumCells) { return -1; } return day; } /** * Called when the user clicks on a day. Handles callbacks to the * {@link OnDayClickListener} if one is set. * * @param day The day that was clicked */ private void onDayClick(int day) { if (mOnDayClickListener != null) { mOnDayClickListener.onDayClick(this, new SimpleMonthAdapter.CalendarDay(mYear, mMonth, day)); } // This is a no-op if accessibility is turned off. mTouchHelper.sendEventForVirtualView(day, AccessibilityEvent.TYPE_VIEW_CLICKED); } /** * @return The date that has accessibility focus, or {@code null} if no date * has focus */ public SimpleMonthAdapter.CalendarDay getAccessibilityFocus() { final int day = mTouchHelper.getFocusedVirtualView(); if (day >= 0) { return new SimpleMonthAdapter.CalendarDay(mYear, mMonth, day); } return null; } /** * Clears accessibility focus within the view. No-op if the view does not * contain accessibility focus. */ public void clearAccessibilityFocus() { mTouchHelper.clearFocusedVirtualView(); } /** * Attempts to restore accessibility focus to the specified date. * * @param day The date which should receive focus * @return {@code false} if the date is not valid for this month view, or * {@code true} if the date received focus */ public boolean restoreAccessibilityFocus(SimpleMonthAdapter.CalendarDay day) { if ((day.year != mYear) || (day.month != mMonth) || (day.day > mNumCells)) { return false; } mTouchHelper.setFocusedVirtualView(day.day); return true; } /** * Provides a virtual view hierarchy for interfacing with an accessibility * service. */ private class MonthViewTouchHelper extends ExploreByTouchHelper { private static final String DATE_FORMAT = "dd MMMM yyyy"; private final Rect mTempRect = new Rect(); private final Calendar mTempCalendar = Calendar.getInstance(); public MonthViewTouchHelper(View host) { super(host); } public void setFocusedVirtualView(int virtualViewId) { getAccessibilityNodeProvider(SimpleMonthView.this).performAction(virtualViewId, AccessibilityNodeInfoCompat.ACTION_ACCESSIBILITY_FOCUS, null); } public void clearFocusedVirtualView() { final int focusedVirtualView = getFocusedVirtualView(); if (focusedVirtualView != ExploreByTouchHelper.INVALID_ID) { getAccessibilityNodeProvider(SimpleMonthView.this).performAction(focusedVirtualView, AccessibilityNodeInfoCompat.ACTION_CLEAR_ACCESSIBILITY_FOCUS, null); } } @Override protected int getVirtualViewAt(float x, float y) { final int day = getDayFromLocation(x, y); if (day >= 0) { return day; } return ExploreByTouchHelper.INVALID_ID; } @Override protected void getVisibleVirtualViews(List<Integer> virtualViewIds) { for (int day = 1; day <= mNumCells; day++) { virtualViewIds.add(day); } } @Override protected void onPopulateEventForVirtualView(int virtualViewId, AccessibilityEvent event) { event.setContentDescription(getItemDescription(virtualViewId)); } @Override protected void onPopulateNodeForVirtualView(int virtualViewId, AccessibilityNodeInfoCompat node) { getItemBounds(virtualViewId, mTempRect); node.setContentDescription(getItemDescription(virtualViewId)); node.setBoundsInParent(mTempRect); node.addAction(AccessibilityNodeInfo.ACTION_CLICK); if (virtualViewId == mSelectedDay) { node.setSelected(true); } } @Override protected boolean onPerformActionForVirtualView(int virtualViewId, int action, Bundle arguments) { switch (action) { case AccessibilityNodeInfo.ACTION_CLICK: onDayClick(virtualViewId); return true; } return false; } /** * Calculates the bounding rectangle of a given time object. * * @param day The day to calculate bounds for * @param rect The rectangle in which to store the bounds */ private void getItemBounds(int day, Rect rect) { final int offsetX = mPadding; final int offsetY = MONTH_HEADER_SIZE; final int cellHeight = mRowHeight; final int cellWidth = ((mWidth - (2 * mPadding)) / mNumDays); final int index = ((day - 1) + findDayOffset()); final int row = (index / mNumDays); final int column = (index % mNumDays); final int x = (offsetX + (column * cellWidth)); final int y = (offsetY + (row * cellHeight)); rect.set(x, y, (x + cellWidth), (y + cellHeight)); } /** * Generates a description for a given time object. Since this * description will be spoken, the components are ordered by descending * specificity as DAY MONTH YEAR. * * @param day The day to generate a description for * @return A description of the time object */ private CharSequence getItemDescription(int day) { mTempCalendar.set(mYear, mMonth, day); final CharSequence date = DateFormat.format(DATE_FORMAT, mTempCalendar.getTimeInMillis()); if (day == mSelectedDay) { return getContext().getString(R.string.item_is_selected, date); } return date; } } /** * Handles callbacks when the user clicks on a time object. */ public interface OnDayClickListener { public void onDayClick(SimpleMonthView view, SimpleMonthAdapter.CalendarDay day); } }