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 com.android.datetimepicker.date; import android.content.Context; import android.content.res.Resources; import android.graphics.drawable.StateListDrawable; import android.support.v4.view.accessibility.AccessibilityEventCompat; import android.support.v4.view.accessibility.AccessibilityRecordCompat; import android.util.Log; import android.view.View; import android.view.ViewGroup; import android.view.accessibility.AccessibilityEvent; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.ArrayAdapter; import android.widget.ListView; import android.widget.TextView; import com.android.datetimepicker.R; import com.android.datetimepicker.Utils; import com.android.datetimepicker.date.DatePickerDialog.OnDateChangedListener; import java.util.ArrayList; import java.util.List; /** * Displays a selectable list of years. */ public class YearPickerView extends ListView implements OnItemClickListener, OnDateChangedListener { private static final String TAG = "YearPickerView"; private final DatePickerController mController; private YearAdapter mAdapter; private int mViewSize; private int mChildSize; private TextViewWithCircularIndicator mSelectedView; /** * @param context */ public YearPickerView(Context context, DatePickerController controller) { super(context); mController = controller; mController.registerOnDateChangedListener(this); ViewGroup.LayoutParams frame = new ViewGroup.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT); setLayoutParams(frame); Resources res = context.getResources(); mViewSize = res.getDimensionPixelOffset(R.dimen.date_picker_view_animator_height); mChildSize = res.getDimensionPixelOffset(R.dimen.year_label_height); setVerticalFadingEdgeEnabled(true); setFadingEdgeLength(mChildSize / 3); init(context); setOnItemClickListener(this); setSelector(new StateListDrawable()); setDividerHeight(0); onDateChanged(); } private void init(Context context) { ArrayList<String> years = new ArrayList<String>(); for (int year = mController.getMinYear(); year <= mController.getMaxYear(); year++) { years.add(String.format("%d", year)); } mAdapter = new YearAdapter(context, R.layout.year_label_text_view, years); setAdapter(mAdapter); } @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { mController.tryVibrate(); TextViewWithCircularIndicator clickedView = (TextViewWithCircularIndicator) view; if (clickedView != null) { if (clickedView != mSelectedView) { if (mSelectedView != null) { mSelectedView.drawIndicator(false); mSelectedView.requestLayout(); } clickedView.drawIndicator(true); clickedView.requestLayout(); mSelectedView = clickedView; } mController.onYearSelected(getYearFromTextView(clickedView)); mAdapter.notifyDataSetChanged(); } } private int getYearFromTextView(TextView view) { return Integer.valueOf(view.getText().toString()); } private class YearAdapter extends ArrayAdapter<String> { public YearAdapter(Context context, int resource, List<String> objects) { super(context, resource, objects); } @Override public View getView(int position, View convertView, ViewGroup parent) { TextViewWithCircularIndicator v = (TextViewWithCircularIndicator) super.getView(position, convertView, parent); v.requestLayout(); int year = getYearFromTextView(v); boolean selected = mController.getSelectedDay().year == year; v.drawIndicator(selected); if (selected) { mSelectedView = v; } return v; } } public void postSetSelectionCentered(final int position) { postSetSelectionFromTop(position, mViewSize / 2 - mChildSize / 2); } public void postSetSelectionFromTop(final int position, final int offset) { post(new Runnable() { @Override public void run() { setSelectionFromTop(position, offset); requestLayout(); } }); } public int getFirstPositionOffset() { final View firstChild = getChildAt(0); if (firstChild == null) { return 0; } return firstChild.getTop(); } @Override public void onDateChanged() { mAdapter.notifyDataSetChanged(); postSetSelectionCentered(mController.getSelectedDay().year - mController.getMinYear()); } @Override public void onInitializeAccessibilityEvent(AccessibilityEvent event) { super.onInitializeAccessibilityEvent(event); if (event.getEventType() == AccessibilityEvent.TYPE_VIEW_SCROLLED) { event.setFromIndex(0); AccessibilityEventCompat.asRecord(event).setToIndex(0); } } }