Java tutorial
/* * Copyright (C) 2012 Google Inc. * Licensed to 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.mail.browse; import android.annotation.SuppressLint; import android.content.Context; import android.content.res.Resources; import android.graphics.Paint.FontMetricsInt; import android.graphics.Typeface; import android.support.v4.view.ViewCompat; import android.util.SparseArray; import android.view.LayoutInflater; import android.view.View; import android.view.View.MeasureSpec; import android.view.ViewGroup; import android.widget.TextView; import com.android.mail.R; import com.android.mail.utils.Utils; import com.android.mail.utils.ViewUtils; import com.google.common.base.Objects; /** * Represents the coordinates of elements inside a CanvasConversationHeaderView * (eg, checkmark, star, subject, sender, folders, etc.) It will inflate a view, * and record the coordinates of each element after layout. This will allows us * to easily improve performance by creating custom view while still defining * layout in XML files. * * @author phamm */ public class ConversationItemViewCoordinates { private static final int SINGLE_LINE = 1; // Left-side gadget modes static final int GADGET_NONE = 0; static final int GADGET_CONTACT_PHOTO = 1; static final int GADGET_CHECKBOX = 2; /** * Simple holder class for an item's abstract configuration state. ListView binding creates an * instance per item, and {@link #forConfig(Context, Config, CoordinatesCache)} uses it to * hide/show optional views and determine the correct coordinates for that item configuration. */ public static final class Config { private int mWidth; private int mGadgetMode = GADGET_NONE; private int mLayoutDirection = View.LAYOUT_DIRECTION_LTR; private boolean mShowFolders = false; private boolean mShowReplyState = false; private boolean mShowColorBlock = false; private boolean mShowPersonalIndicator = false; private boolean mUseFullMargins = false; public Config withGadget(int gadget) { mGadgetMode = gadget; return this; } public Config showFolders() { mShowFolders = true; return this; } public Config showReplyState() { mShowReplyState = true; return this; } public Config showColorBlock() { mShowColorBlock = true; return this; } public Config showPersonalIndicator() { mShowPersonalIndicator = true; return this; } public Config updateWidth(int width) { mWidth = width; return this; } public int getWidth() { return mWidth; } public int getGadgetMode() { return mGadgetMode; } public boolean areFoldersVisible() { return mShowFolders; } public boolean isReplyStateVisible() { return mShowReplyState; } public boolean isColorBlockVisible() { return mShowColorBlock; } public boolean isPersonalIndicatorVisible() { return mShowPersonalIndicator; } private int getCacheKey() { // hash the attributes that contribute to item height and child view geometry return Objects.hashCode(mWidth, mGadgetMode, mShowFolders, mShowReplyState, mShowPersonalIndicator, mLayoutDirection, mUseFullMargins); } public Config setLayoutDirection(int layoutDirection) { mLayoutDirection = layoutDirection; return this; } public int getLayoutDirection() { return mLayoutDirection; } public Config setUseFullMargins(boolean useFullMargins) { mUseFullMargins = useFullMargins; return this; } public boolean useFullPadding() { return mUseFullMargins; } } public static class CoordinatesCache { private final SparseArray<ConversationItemViewCoordinates> mCoordinatesCache = new SparseArray<ConversationItemViewCoordinates>(); private final SparseArray<View> mViewsCache = new SparseArray<View>(); public ConversationItemViewCoordinates getCoordinates(final int key) { return mCoordinatesCache.get(key); } public View getView(final int layoutId) { return mViewsCache.get(layoutId); } public void put(final int key, final ConversationItemViewCoordinates coords) { mCoordinatesCache.put(key, coords); } public void put(final int layoutId, final View view) { mViewsCache.put(layoutId, view); } } final int height; // Star. final int starX; final int starY; final int starWidth; // Senders. final int sendersX; final int sendersY; final int sendersWidth; final int sendersHeight; final int sendersLineCount; final float sendersFontSize; // Subject. final int subjectX; final int subjectY; final int subjectWidth; final int subjectHeight; final float subjectFontSize; // Snippet. final int snippetX; final int snippetY; final int maxSnippetWidth; final int snippetHeight; final float snippetFontSize; // Folders. final int folderLayoutWidth; final int folderCellWidth; final int foldersLeft; final int foldersRight; final int foldersY; final Typeface foldersTypeface; final float foldersFontSize; // Info icon final int infoIconX; final int infoIconXRight; final int infoIconY; // Date. final int dateX; final int dateXRight; final int dateY; final int datePaddingStart; final float dateFontSize; final int dateYBaseline; // Paperclip. final int paperclipY; final int paperclipPaddingStart; // Color block. final int colorBlockX; final int colorBlockY; final int colorBlockWidth; final int colorBlockHeight; // Reply state of a conversation. final int replyStateX; final int replyStateY; final int personalIndicatorX; final int personalIndicatorY; final int contactImagesHeight; final int contactImagesWidth; final int contactImagesX; final int contactImagesY; private ConversationItemViewCoordinates(final Context context, final Config config, final CoordinatesCache cache) { Utils.traceBeginSection("CIV coordinates constructor"); final Resources res = context.getResources(); final int layoutId = R.layout.conversation_item_view; ViewGroup view = (ViewGroup) cache.getView(layoutId); if (view == null) { view = (ViewGroup) LayoutInflater.from(context).inflate(layoutId, null); cache.put(layoutId, view); } // Show/hide optional views before measure/layout call final TextView folders = (TextView) view.findViewById(R.id.folders); folders.setVisibility(config.areFoldersVisible() ? View.VISIBLE : View.GONE); View contactImagesView = view.findViewById(R.id.contact_image); switch (config.getGadgetMode()) { case GADGET_CONTACT_PHOTO: contactImagesView.setVisibility(View.VISIBLE); break; case GADGET_CHECKBOX: contactImagesView.setVisibility(View.GONE); contactImagesView = null; break; default: contactImagesView.setVisibility(View.GONE); contactImagesView = null; break; } final View replyState = view.findViewById(R.id.reply_state); replyState.setVisibility(config.isReplyStateVisible() ? View.VISIBLE : View.GONE); final View personalIndicator = view.findViewById(R.id.personal_indicator); personalIndicator.setVisibility(config.isPersonalIndicatorVisible() ? View.VISIBLE : View.GONE); setFramePadding(context, view, config.useFullPadding()); // Layout the appropriate view. ViewCompat.setLayoutDirection(view, config.getLayoutDirection()); final int widthSpec = MeasureSpec.makeMeasureSpec(config.getWidth(), MeasureSpec.EXACTLY); final int heightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); view.measure(widthSpec, heightSpec); view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight()); // Once the view is measured, let's calculate the dynamic width variables. folderLayoutWidth = (int) (view.getWidth() * res.getInteger(R.integer.folder_max_width_proportion) / 100.0); folderCellWidth = (int) (view.getWidth() * res.getInteger(R.integer.folder_cell_max_width_proportion) / 100.0); // Utils.dumpViewTree((ViewGroup) view); // Records coordinates. // Contact images view if (contactImagesView != null) { contactImagesWidth = contactImagesView.getWidth(); contactImagesHeight = contactImagesView.getHeight(); contactImagesX = getX(contactImagesView); contactImagesY = getY(contactImagesView); } else { contactImagesX = contactImagesY = contactImagesWidth = contactImagesHeight = 0; } final boolean isRtl = ViewUtils.isViewRtl(view); final View star = view.findViewById(R.id.star); final int starPadding = res.getDimensionPixelSize(R.dimen.conv_list_star_padding_start); starX = getX(star) + (isRtl ? 0 : starPadding); starY = getY(star); starWidth = star.getWidth(); final TextView senders = (TextView) view.findViewById(R.id.senders); final int sendersTopAdjust = getLatinTopAdjustment(senders); sendersX = getX(senders); sendersY = getY(senders) + sendersTopAdjust; sendersWidth = senders.getWidth(); sendersHeight = senders.getHeight(); sendersLineCount = SINGLE_LINE; sendersFontSize = senders.getTextSize(); final TextView subject = (TextView) view.findViewById(R.id.subject); final int subjectTopAdjust = getLatinTopAdjustment(subject); subjectX = getX(subject); subjectY = getY(subject) + subjectTopAdjust; subjectWidth = subject.getWidth(); subjectHeight = subject.getHeight(); subjectFontSize = subject.getTextSize(); final TextView snippet = (TextView) view.findViewById(R.id.snippet); final int snippetTopAdjust = getLatinTopAdjustment(snippet); snippetX = getX(snippet); snippetY = getY(snippet) + snippetTopAdjust; maxSnippetWidth = snippet.getWidth(); snippetHeight = snippet.getHeight(); snippetFontSize = snippet.getTextSize(); if (config.areFoldersVisible()) { foldersLeft = getX(folders); foldersRight = foldersLeft + folders.getWidth(); foldersY = getY(folders); foldersTypeface = folders.getTypeface(); foldersFontSize = folders.getTextSize(); } else { foldersLeft = 0; foldersRight = 0; foldersY = 0; foldersTypeface = null; foldersFontSize = 0; } final View colorBlock = view.findViewById(R.id.color_block); if (config.isColorBlockVisible() && colorBlock != null) { colorBlockX = getX(colorBlock); colorBlockY = getY(colorBlock); colorBlockWidth = colorBlock.getWidth(); colorBlockHeight = colorBlock.getHeight(); } else { colorBlockX = colorBlockY = colorBlockWidth = colorBlockHeight = 0; } if (config.isReplyStateVisible()) { replyStateX = getX(replyState); replyStateY = getY(replyState); } else { replyStateX = replyStateY = 0; } if (config.isPersonalIndicatorVisible()) { personalIndicatorX = getX(personalIndicator); personalIndicatorY = getY(personalIndicator); } else { personalIndicatorX = personalIndicatorY = 0; } final View infoIcon = view.findViewById(R.id.info_icon); infoIconX = getX(infoIcon); infoIconXRight = infoIconX + infoIcon.getWidth(); infoIconY = getY(infoIcon); final TextView date = (TextView) view.findViewById(R.id.date); dateX = getX(date); dateXRight = dateX + date.getWidth(); dateY = getY(date); datePaddingStart = ViewUtils.getPaddingStart(date); dateFontSize = date.getTextSize(); dateYBaseline = dateY + getLatinTopAdjustment(date) + date.getBaseline(); final View paperclip = view.findViewById(R.id.paperclip); paperclipY = getY(paperclip); paperclipPaddingStart = ViewUtils.getPaddingStart(paperclip); height = view.getHeight() + sendersTopAdjust; Utils.traceEndSection(); } @SuppressLint("NewApi") private static void setFramePadding(Context context, ViewGroup view, boolean useFullPadding) { final Resources res = context.getResources(); final int padding = res.getDimensionPixelSize( useFullPadding ? R.dimen.conv_list_card_border_padding : R.dimen.conv_list_no_border_padding); final View frame = view.findViewById(R.id.conversation_item_frame); if (Utils.isRunningJBMR1OrLater()) { // start, top, end, bottom frame.setPaddingRelative(frame.getPaddingStart(), padding, frame.getPaddingEnd(), padding); } else { frame.setPadding(frame.getPaddingLeft(), padding, frame.getPaddingRight(), padding); } } /** * Returns a negative corrective value that you can apply to a TextView's vertical dimensions * that will nudge the first line of text upwards such that uppercase Latin characters are * truly top-aligned. * <p> * N.B. this will cause other characters to draw above the top! only use this if you have * adequate top margin. * */ private static int getLatinTopAdjustment(TextView t) { final FontMetricsInt fmi = t.getPaint().getFontMetricsInt(); return (fmi.top - fmi.ascent); } /** * Returns the x coordinates of a view by tracing up its hierarchy. */ private static int getX(View view) { int x = 0; while (view != null) { x += (int) view.getX(); view = (View) view.getParent(); } return x; } /** * Returns the y coordinates of a view by tracing up its hierarchy. */ private static int getY(View view) { int y = 0; while (view != null) { y += (int) view.getY(); view = (View) view.getParent(); } return y; } /** * Returns the length (maximum of characters) of subject in this mode. */ public static int getSendersLength(Context context, boolean hasAttachments) { final Resources res = context.getResources(); if (hasAttachments) { return res.getInteger(R.integer.senders_with_attachment_lengths); } else { return res.getInteger(R.integer.senders_lengths); } } /** * Returns coordinates for elements inside a conversation header view given * the view width. */ public static ConversationItemViewCoordinates forConfig(final Context context, final Config config, final CoordinatesCache cache) { final int cacheKey = config.getCacheKey(); ConversationItemViewCoordinates coordinates = cache.getCoordinates(cacheKey); if (coordinates != null) { return coordinates; } coordinates = new ConversationItemViewCoordinates(context, config, cache); cache.put(cacheKey, coordinates); return coordinates; } }