ControlBarPresenter.java revision 4cc255c1c9ce5f3a718970b6e0be2c3ae6abf9ed
1/* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 5 * in compliance with the License. You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software distributed under the License 10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 11 * or implied. See the License for the specific language governing permissions and limitations under 12 * the License. 13 */ 14package android.support.v17.leanback.widget; 15 16import android.content.Context; 17import android.support.v17.leanback.R; 18import android.util.SparseArray; 19import android.view.LayoutInflater; 20import android.view.View; 21import android.view.ViewGroup; 22import android.widget.LinearLayout; 23 24/** 25 * A presenter that assumes a LinearLayout container for a series 26 * of control buttons backed by objects of type {@link Action}. 27 * 28 * Different layouts may be passed to the presenter constructor. 29 * The layout must contain a view with id control_bar. 30 */ 31class ControlBarPresenter extends Presenter { 32 33 private static final int MAX_CONTROLS = 7; 34 35 /** 36 * The data type expected by this presenter. 37 */ 38 static class BoundData { 39 /** 40 * Adapter containing objects of type {@link Action}. 41 */ 42 ObjectAdapter adapter; 43 44 /** 45 * The presenter to be used for the adapter objects. 46 */ 47 Presenter presenter; 48 } 49 50 /** 51 * A ViewHolder for an actions bar. 52 */ 53 class ViewHolder extends Presenter.ViewHolder { 54 ObjectAdapter mAdapter; 55 Presenter mPresenter; 56 ControlBar mControlBar; 57 SparseArray<Presenter.ViewHolder> mViewHolders = 58 new SparseArray<Presenter.ViewHolder>(); 59 ObjectAdapter.DataObserver mDataObserver; 60 61 /** 62 * Constructor for the ViewHolder. 63 */ 64 ViewHolder(View rootView) { 65 super(rootView); 66 mControlBar = (ControlBar) rootView.findViewById(R.id.control_bar); 67 if (mControlBar == null) { 68 throw new IllegalStateException("Couldn't find control_bar"); 69 } 70 mControlBar.setOnChildFocusedListener(new ControlBar.OnChildFocusedListener() { 71 @Override 72 public void onChildFocusedListener(View child, View focused) { 73 if (mOnItemViewSelectedListener == null) { 74 return; 75 } 76 for (int position = 0; position < mViewHolders.size(); position++) { 77 if (mViewHolders.get(position).view == child) { 78 mOnItemViewSelectedListener.onItemSelected( 79 mViewHolders.get(position), getAdapter().get(position), 80 null, null); 81 break; 82 } 83 } 84 } 85 }); 86 mDataObserver = new ObjectAdapter.DataObserver() { 87 @Override 88 public void onChanged() { 89 showControls(mAdapter, mPresenter); 90 } 91 @Override 92 public void onItemRangeChanged(int positionStart, int itemCount) { 93 for (int i = 0; i < itemCount; i++) { 94 bindControlToAction(positionStart + i, mAdapter, mPresenter); 95 } 96 } 97 }; 98 } 99 100 int getChildMarginFromCenter(Context context, int numControls) { 101 // Includes margin between icons plus two times half the icon width. 102 return getChildMarginDefault(context) + getControlIconWidth(context); 103 } 104 105 void showControls(ObjectAdapter adapter, Presenter presenter) { 106 View focusedChild = mControlBar.getFocusedChild(); 107 mControlBar.removeAllViews(); 108 for (int position = 0; position < adapter.size() && position < MAX_CONTROLS; 109 position++) { 110 bindControlToAction(position, adapter, presenter); 111 } 112 if (focusedChild != null) { 113 focusedChild.requestFocus(); 114 } 115 mControlBar.setChildMarginFromCenter( 116 getChildMarginFromCenter(mControlBar.getContext(), adapter.size())); 117 } 118 119 void bindControlToAction(final int position, ObjectAdapter adapter, Presenter presenter) { 120 Presenter.ViewHolder vh = mViewHolders.get(position); 121 Object item = adapter.get(position); 122 if (vh == null) { 123 vh = presenter.onCreateViewHolder(mControlBar); 124 mViewHolders.put(position, vh); 125 presenter.setOnClickListener(vh, new View.OnClickListener() { 126 @Override 127 public void onClick(View v) { 128 Object item = getAdapter().get(position); 129 if (mOnActionClickedListener != null && item instanceof Action) { 130 mOnActionClickedListener.onActionClicked((Action) item); 131 } 132 } 133 }); 134 } 135 if (vh.view.getParent() == null) { 136 mControlBar.addView(vh.view); 137 } 138 presenter.onBindViewHolder(vh, item); 139 } 140 141 ObjectAdapter getAdapter() { 142 return mAdapter; 143 } 144 } 145 146 private OnActionClickedListener mOnActionClickedListener; 147 private OnItemViewSelectedListener mOnItemViewSelectedListener; 148 private int mLayoutResourceId; 149 private static int sChildMarginDefault; 150 private static int sControlIconWidth; 151 152 /** 153 * Constructor for a ControlBarPresenter. 154 * 155 * @param layoutResourceId The resource id of the layout for this presenter. 156 */ 157 public ControlBarPresenter(int layoutResourceId) { 158 mLayoutResourceId = layoutResourceId; 159 } 160 161 /** 162 * Returns the layout resource id. 163 */ 164 public int getLayoutResourceId() { 165 return mLayoutResourceId; 166 } 167 168 /** 169 * Sets the listener for {@link Action} click events. 170 */ 171 public void setOnActionClickedListener(OnActionClickedListener listener) { 172 mOnActionClickedListener = listener; 173 } 174 175 /** 176 * Gets the listener for {@link Action} click events. 177 */ 178 public OnActionClickedListener getOnActionClickedListener() { 179 return mOnActionClickedListener; 180 } 181 182 /** 183 * Sets the listener for item selection. When this listener is invoked, 184 * the rowViewHolder and row are always null. 185 */ 186 public void setOnItemViewSelectedListener(OnItemViewSelectedListener listener) { 187 mOnItemViewSelectedListener = listener; 188 } 189 190 /** 191 * Gets the listener for item selection. 192 */ 193 public OnItemViewSelectedListener getOnItemViewSelectedListener() { 194 return mOnItemViewSelectedListener; 195 } 196 197 @Override 198 public Presenter.ViewHolder onCreateViewHolder(ViewGroup parent) { 199 View v = LayoutInflater.from(parent.getContext()) 200 .inflate(getLayoutResourceId(), parent, false); 201 return new ViewHolder(v); 202 } 203 204 @Override 205 public void onBindViewHolder(Presenter.ViewHolder holder, Object item) { 206 ViewHolder vh = (ViewHolder) holder; 207 BoundData data = (BoundData) item; 208 if (vh.mAdapter != data.adapter) { 209 vh.mAdapter = data.adapter; 210 vh.mAdapter.registerObserver(vh.mDataObserver); 211 } 212 vh.mPresenter = data.presenter; 213 vh.showControls(vh.mAdapter, vh.mPresenter); 214 } 215 216 @Override 217 public void onUnbindViewHolder(Presenter.ViewHolder holder) { 218 ViewHolder vh = (ViewHolder) holder; 219 vh.mAdapter.unregisterObserver(vh.mDataObserver); 220 vh.mAdapter = null; 221 } 222 223 int getChildMarginDefault(Context context) { 224 if (sChildMarginDefault == 0) { 225 sChildMarginDefault = context.getResources().getDimensionPixelSize( 226 R.dimen.lb_playback_controls_child_margin_default); 227 } 228 return sChildMarginDefault; 229 } 230 231 int getControlIconWidth(Context context) { 232 if (sControlIconWidth == 0) { 233 sControlIconWidth = context.getResources().getDimensionPixelSize( 234 R.dimen.lb_control_icon_width); 235 } 236 return sControlIconWidth; 237 } 238} 239