Java tutorial
/* * Copyright (C) 2015 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.marlonjones.voidlauncher.allapps; import android.content.Context; import android.content.Intent; import android.content.res.Resources; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Point; import android.graphics.PointF; import android.graphics.Rect; import android.support.v4.view.accessibility.AccessibilityEventCompat; import android.support.v4.view.accessibility.AccessibilityRecordCompat; import android.support.v7.widget.GridLayoutManager; import android.support.v7.widget.RecyclerView; import android.view.Gravity; import android.view.LayoutInflater; import android.view.View; import android.view.View.OnFocusChangeListener; import android.view.ViewConfiguration; import android.view.ViewGroup; import android.view.accessibility.AccessibilityEvent; import android.widget.TextView; import com.marlonjones.voidlauncher.AppInfo; import com.marlonjones.voidlauncher.BubbleTextView; import com.marlonjones.voidlauncher.DeviceProfile; import com.marlonjones.voidlauncher.Launcher; import com.marlonjones.voidlauncher.R; import com.marlonjones.voidlauncher.Utilities; import java.util.HashMap; import java.util.List; /** * The grid view adapter of all the apps. */ public class AllAppsGridAdapter extends RecyclerView.Adapter<AllAppsGridAdapter.ViewHolder> { public static final String TAG = "AppsGridAdapter"; private static final boolean DEBUG = false; // A section break in the grid public static final int VIEW_TYPE_SECTION_BREAK = 1 << 0; // A normal icon public static final int VIEW_TYPE_ICON = 1 << 1; // A prediction icon public static final int VIEW_TYPE_PREDICTION_ICON = 1 << 2; // The message shown when there are no filtered results public static final int VIEW_TYPE_EMPTY_SEARCH = 1 << 3; // The message to continue to a market search when there are no filtered results public static final int VIEW_TYPE_SEARCH_MARKET = 1 << 4; // We use various dividers for various purposes. They share enough attributes to reuse layouts, // but differ in enough attributes to require different view types // A divider that separates the apps list and the search market button public static final int VIEW_TYPE_SEARCH_MARKET_DIVIDER = 1 << 5; // The divider under the search field public static final int VIEW_TYPE_SEARCH_DIVIDER = 1 << 6; // The divider that separates prediction icons from the app list public static final int VIEW_TYPE_PREDICTION_DIVIDER = 1 << 7; // Common view type masks public static final int VIEW_TYPE_MASK_DIVIDER = VIEW_TYPE_SEARCH_DIVIDER | VIEW_TYPE_SEARCH_MARKET_DIVIDER | VIEW_TYPE_PREDICTION_DIVIDER | VIEW_TYPE_SECTION_BREAK; public static final int VIEW_TYPE_MASK_ICON = VIEW_TYPE_ICON | VIEW_TYPE_PREDICTION_ICON; public interface BindViewCallback { public void onBindView(ViewHolder holder); } /** * ViewHolder for each icon. */ public static class ViewHolder extends RecyclerView.ViewHolder { public View mContent; public ViewHolder(View v) { super(v); mContent = v; } } /** * A subclass of GridLayoutManager that overrides accessibility values during app search. */ public class AppsGridLayoutManager extends GridLayoutManager { public AppsGridLayoutManager(Context context) { super(context, 1, GridLayoutManager.VERTICAL, false); } @Override public void onInitializeAccessibilityEvent(AccessibilityEvent event) { super.onInitializeAccessibilityEvent(event); // Ensure that we only report the number apps for accessibility not including other // adapter views final AccessibilityRecordCompat record = AccessibilityEventCompat.asRecord(event); record.setItemCount(mApps.getNumFilteredApps()); } @Override public int getRowCountForAccessibility(RecyclerView.Recycler recycler, RecyclerView.State state) { if (mApps.hasNoFilteredResults()) { // Disregard the no-search-results text as a list item for accessibility return 0; } else { return super.getRowCountForAccessibility(recycler, state); } } @Override public int getPaddingBottom() { return mLauncher.getDragLayer().getInsets().bottom; } } /** * Helper class to size the grid items. */ public class GridSpanSizer extends GridLayoutManager.SpanSizeLookup { public GridSpanSizer() { super(); setSpanIndexCacheEnabled(true); } @Override public int getSpanSize(int position) { if (isIconViewType(mApps.getAdapterItems().get(position).viewType)) { return 1; } else { // Section breaks span the full width return mAppsPerRow; } } } /** * Helper class to draw the section headers */ public class GridItemDecoration extends RecyclerView.ItemDecoration { private static final boolean DEBUG_SECTION_MARGIN = false; private static final boolean FADE_OUT_SECTIONS = false; private HashMap<String, PointF> mCachedSectionBounds = new HashMap<>(); private Rect mTmpBounds = new Rect(); @Override public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) { if (mApps.hasFilter() || mAppsPerRow == 0) { return; } if (DEBUG_SECTION_MARGIN) { Paint p = new Paint(); p.setColor(0x33ff0000); c.drawRect(mBackgroundPadding.left, 0, mBackgroundPadding.left + mSectionNamesMargin, parent.getMeasuredHeight(), p); } List<AlphabeticalAppsList.AdapterItem> items = mApps.getAdapterItems(); boolean showSectionNames = mSectionNamesMargin > 0; int childCount = parent.getChildCount(); int lastSectionTop = 0; int lastSectionHeight = 0; for (int i = 0; i < childCount; i++) { View child = parent.getChildAt(i); ViewHolder holder = (ViewHolder) parent.getChildViewHolder(child); if (!isValidHolderAndChild(holder, child, items)) { continue; } if (showSectionNames && shouldDrawItemSection(holder, i, items)) { // At this point, we only draw sections for each section break; int viewTopOffset = (2 * child.getPaddingTop()); int pos = holder.getPosition(); AlphabeticalAppsList.AdapterItem item = items.get(pos); AlphabeticalAppsList.SectionInfo sectionInfo = item.sectionInfo; // Draw all the sections for this index String lastSectionName = item.sectionName; for (int j = item.sectionAppIndex; j < sectionInfo.numApps; j++, pos++) { AlphabeticalAppsList.AdapterItem nextItem = items.get(pos); String sectionName = nextItem.sectionName; if (nextItem.sectionInfo != sectionInfo) { break; } if (j > item.sectionAppIndex && sectionName.equals(lastSectionName)) { continue; } // Find the section name bounds PointF sectionBounds = getAndCacheSectionBounds(sectionName); // Calculate where to draw the section int sectionBaseline = (int) (viewTopOffset + sectionBounds.y); int x = mIsRtl ? parent.getWidth() - mBackgroundPadding.left - mSectionNamesMargin : mBackgroundPadding.left; x += (int) ((mSectionNamesMargin - sectionBounds.x) / 2f); int y = child.getTop() + sectionBaseline; // Determine whether this is the last row with apps in that section, if // so, then fix the section to the row allowing it to scroll past the // baseline, otherwise, bound it to the baseline so it's in the viewport int appIndexInSection = items.get(pos).sectionAppIndex; int nextRowPos = Math.min(items.size() - 1, pos + mAppsPerRow - (appIndexInSection % mAppsPerRow)); AlphabeticalAppsList.AdapterItem nextRowItem = items.get(nextRowPos); boolean fixedToRow = !sectionName.equals(nextRowItem.sectionName); if (!fixedToRow) { y = Math.max(sectionBaseline, y); } // In addition, if it overlaps with the last section that was drawn, then // offset it so that it does not overlap if (lastSectionHeight > 0 && y <= (lastSectionTop + lastSectionHeight)) { y += lastSectionTop - y + lastSectionHeight; } // Draw the section header if (FADE_OUT_SECTIONS) { int alpha = 255; if (fixedToRow) { alpha = Math.min(255, (int) (255 * (Math.max(0, y) / (float) sectionBaseline))); } mSectionTextPaint.setAlpha(alpha); } c.drawText(sectionName, x, y, mSectionTextPaint); lastSectionTop = y; lastSectionHeight = (int) (sectionBounds.y + mSectionHeaderOffset); lastSectionName = sectionName; } i += (sectionInfo.numApps - item.sectionAppIndex); } } } @Override public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) { // Do nothing } /** * Given a section name, return the bounds of the given section name. */ private PointF getAndCacheSectionBounds(String sectionName) { PointF bounds = mCachedSectionBounds.get(sectionName); if (bounds == null) { mSectionTextPaint.getTextBounds(sectionName, 0, sectionName.length(), mTmpBounds); bounds = new PointF(mSectionTextPaint.measureText(sectionName), mTmpBounds.height()); mCachedSectionBounds.put(sectionName, bounds); } return bounds; } /** * Returns whether we consider this a valid view holder for us to draw a divider or section for. */ private boolean isValidHolderAndChild(ViewHolder holder, View child, List<AlphabeticalAppsList.AdapterItem> items) { // Ensure item is not already removed GridLayoutManager.LayoutParams lp = (GridLayoutManager.LayoutParams) child.getLayoutParams(); if (lp.isItemRemoved()) { return false; } // Ensure we have a valid holder if (holder == null) { return false; } // Ensure we have a holder position int pos = holder.getPosition(); if (pos < 0 || pos >= items.size()) { return false; } return true; } /** * Returns whether to draw the section for the given child. */ private boolean shouldDrawItemSection(ViewHolder holder, int childIndex, List<AlphabeticalAppsList.AdapterItem> items) { int pos = holder.getPosition(); AlphabeticalAppsList.AdapterItem item = items.get(pos); // Ensure it's an icon if (item.viewType != AllAppsGridAdapter.VIEW_TYPE_ICON) { return false; } // Draw the section header for the first item in each section return (childIndex == 0) || (items.get(pos - 1).viewType == AllAppsGridAdapter.VIEW_TYPE_SECTION_BREAK); } } private final Launcher mLauncher; private final LayoutInflater mLayoutInflater; private final AlphabeticalAppsList mApps; private final GridLayoutManager mGridLayoutMgr; private final GridSpanSizer mGridSizer; private final GridItemDecoration mItemDecoration; private final View.OnClickListener mIconClickListener; private final View.OnLongClickListener mIconLongClickListener; private final Rect mBackgroundPadding = new Rect(); private final boolean mIsRtl; // Section drawing @Deprecated private final int mSectionNamesMargin; @Deprecated private final int mSectionHeaderOffset; private final Paint mSectionTextPaint; private int mAppsPerRow; private BindViewCallback mBindViewCallback; private AllAppsSearchBarController mSearchController; private OnFocusChangeListener mIconFocusListener; // The text to show when there are no search results and no market search handler. private String mEmptySearchMessage; // The intent to send off to the market app, updated each time the search query changes. private Intent mMarketSearchIntent; public AllAppsGridAdapter(Launcher launcher, AlphabeticalAppsList apps, View.OnClickListener iconClickListener, View.OnLongClickListener iconLongClickListener) { Resources res = launcher.getResources(); mLauncher = launcher; mApps = apps; mEmptySearchMessage = res.getString(R.string.all_apps_loading_message); mGridSizer = new GridSpanSizer(); mGridLayoutMgr = new AppsGridLayoutManager(launcher); mGridLayoutMgr.setSpanSizeLookup(mGridSizer); mItemDecoration = new GridItemDecoration(); mLayoutInflater = LayoutInflater.from(launcher); mIconClickListener = iconClickListener; mIconLongClickListener = iconLongClickListener; mSectionNamesMargin = res.getDimensionPixelSize(R.dimen.all_apps_grid_view_start_margin); mSectionHeaderOffset = res.getDimensionPixelSize(R.dimen.all_apps_grid_section_y_offset); mIsRtl = Utilities.isRtl(res); mSectionTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mSectionTextPaint.setTextSize(res.getDimensionPixelSize(R.dimen.all_apps_grid_section_text_size)); mSectionTextPaint.setColor(Utilities.getColorAccent(launcher)); } public static boolean isDividerViewType(int viewType) { return isViewType(viewType, VIEW_TYPE_MASK_DIVIDER); } public static boolean isIconViewType(int viewType) { return isViewType(viewType, VIEW_TYPE_MASK_ICON); } public static boolean isViewType(int viewType, int viewTypeMask) { return (viewType & viewTypeMask) != 0; } /** * Sets the number of apps per row. */ public void setNumAppsPerRow(int appsPerRow) { mAppsPerRow = appsPerRow; mGridLayoutMgr.setSpanCount(appsPerRow); } public void setSearchController(AllAppsSearchBarController searchController) { mSearchController = searchController; } public void setIconFocusListener(OnFocusChangeListener focusListener) { mIconFocusListener = focusListener; } /** * Sets the last search query that was made, used to show when there are no results and to also * seed the intent for searching the market. */ public void setLastSearchQuery(String query) { Resources res = mLauncher.getResources(); mEmptySearchMessage = res.getString(R.string.all_apps_no_search_results, query); mMarketSearchIntent = mSearchController.createMarketSearchIntent(query); } /** * Sets the callback for when views are bound. */ public void setBindViewCallback(BindViewCallback cb) { mBindViewCallback = cb; } /** * Notifies the adapter of the background padding so that it can draw things correctly in the * item decorator. */ public void updateBackgroundPadding(Rect padding) { mBackgroundPadding.set(padding); } /** * Returns the grid layout manager. */ public GridLayoutManager getLayoutManager() { return mGridLayoutMgr; } /** * Returns the item decoration for the recycler view. */ public RecyclerView.ItemDecoration getItemDecoration() { // We don't draw any headers when we are uncomfortably dense return mItemDecoration; } @Override public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { switch (viewType) { case VIEW_TYPE_SECTION_BREAK: return new ViewHolder(new View(parent.getContext())); case VIEW_TYPE_ICON: /* falls through */ case VIEW_TYPE_PREDICTION_ICON: { BubbleTextView icon = (BubbleTextView) mLayoutInflater.inflate(R.layout.all_apps_icon, parent, false); icon.setOnClickListener(mIconClickListener); icon.setOnLongClickListener(mIconLongClickListener); icon.setLongPressTimeout(ViewConfiguration.get(parent.getContext()).getLongPressTimeout()); icon.setOnFocusChangeListener(mIconFocusListener); // Ensure the all apps icon height matches the workspace icons DeviceProfile profile = mLauncher.getDeviceProfile(); Point cellSize = profile.getCellSize(); GridLayoutManager.LayoutParams lp = (GridLayoutManager.LayoutParams) icon.getLayoutParams(); lp.height = cellSize.y; icon.setLayoutParams(lp); return new ViewHolder(icon); } case VIEW_TYPE_EMPTY_SEARCH: return new ViewHolder(mLayoutInflater.inflate(R.layout.all_apps_empty_search, parent, false)); case VIEW_TYPE_SEARCH_MARKET: View searchMarketView = mLayoutInflater.inflate(R.layout.all_apps_search_market, parent, false); searchMarketView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { mLauncher.startActivitySafely(v, mMarketSearchIntent, null); } }); return new ViewHolder(searchMarketView); case VIEW_TYPE_SEARCH_DIVIDER: return new ViewHolder(mLayoutInflater.inflate(R.layout.all_apps_search_divider, parent, false)); case VIEW_TYPE_PREDICTION_DIVIDER: /* falls through */ case VIEW_TYPE_SEARCH_MARKET_DIVIDER: return new ViewHolder(mLayoutInflater.inflate(R.layout.all_apps_divider, parent, false)); default: throw new RuntimeException("Unexpected view type"); } } @Override public void onBindViewHolder(ViewHolder holder, int position) { switch (holder.getItemViewType()) { case VIEW_TYPE_ICON: { AppInfo info = mApps.getAdapterItems().get(position).appInfo; BubbleTextView icon = (BubbleTextView) holder.mContent; icon.applyFromApplicationInfo(info); icon.setAccessibilityDelegate(mLauncher.getAccessibilityDelegate()); break; } case VIEW_TYPE_PREDICTION_ICON: { AppInfo info = mApps.getAdapterItems().get(position).appInfo; BubbleTextView icon = (BubbleTextView) holder.mContent; icon.applyFromApplicationInfo(info); icon.setAccessibilityDelegate(mLauncher.getAccessibilityDelegate()); break; } case VIEW_TYPE_EMPTY_SEARCH: TextView emptyViewText = (TextView) holder.mContent; emptyViewText.setText(mEmptySearchMessage); emptyViewText.setGravity( mApps.hasNoFilteredResults() ? Gravity.CENTER : Gravity.START | Gravity.CENTER_VERTICAL); break; case VIEW_TYPE_SEARCH_MARKET: TextView searchView = (TextView) holder.mContent; if (mMarketSearchIntent != null) { searchView.setVisibility(View.VISIBLE); } else { searchView.setVisibility(View.GONE); } break; } if (mBindViewCallback != null) { mBindViewCallback.onBindView(holder); } } @Override public boolean onFailedToRecycleView(ViewHolder holder) { // Always recycle and we will reset the view when it is bound return true; } @Override public int getItemCount() { return mApps.getAdapterItems().size(); } @Override public int getItemViewType(int position) { AlphabeticalAppsList.AdapterItem item = mApps.getAdapterItems().get(position); return item.viewType; } }