// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package org.chromium.chrome.browser.tab;
import android.content.res.Resources;
import android.graphics.Bitmap;
import androidx.annotation.Nullable;
import androidx.annotation.VisibleForTesting;
import org.jni_zero.CalledByNative;
import org.jni_zero.NativeMethods;
import org.chromium.base.ObserverList.RewindableIterator;
import org.chromium.chrome.R;
import org.chromium.content_public.browser.WebContents;
import org.chromium.url.GURL;
/** Fetches a favicon for active WebContents in a Tab. */
public class TabFavicon extends TabWebContentsUserData {
private static final Class<TabFavicon> USER_DATA_KEY = TabFavicon.class;
private final TabImpl mTab;
private final long mNativeTabFavicon;
/**
* The size in pixels at which favicons will be drawn. Ideally mFavicon will have this size to
* avoid scaling artifacts.
*/
private final int mIdealFaviconSize;
// The ideal favicon size for navigation transitions, in DIP.
private final int mNavigationTransitionsIdealFaviconSize;
// The current favicon width and height for navigation transitions.
private int mNavigationTransitionsFaviconWidth;
private int mNavigationTransitionsFaviconHeight;
// The URL of the tab when the favicon was fetch for navigation transitions.
private GURL mFaviconTabUrlForNavigationTransition;
private Bitmap mFavicon;
private int mFaviconWidth;
private int mFaviconHeight;
// The URL of the tab when mFavicon was fetched.
private GURL mFaviconTabUrl;
static TabFavicon from(Tab tab) {
TabFavicon favicon = get(tab);
if (favicon == null) {
favicon = tab.getUserDataHost().setUserData(USER_DATA_KEY, new TabFavicon(tab));
}
return favicon;
}
private static TabFavicon get(Tab tab) {
if (tab == null || !tab.isInitialized()) return null;
return tab.getUserDataHost().getUserData(USER_DATA_KEY);
}
/**
* @param tab Tab containing the web contents's favicon.
* @return {@link Bitmap} of the favicon.
*/
public static @Nullable Bitmap getBitmap(Tab tab) {
TabFavicon tabFavicon = get(tab);
return tabFavicon != null ? tabFavicon.getFavicon() : null;
}
private TabFavicon(Tab tab) {
super(tab);
mTab = (TabImpl) tab;
Resources resources = mTab.getThemedApplicationContext().getResources();
mIdealFaviconSize = resources.getDimensionPixelSize(R.dimen.default_favicon_size);
mNavigationTransitionsIdealFaviconSize =
resources.getDimensionPixelSize(R.dimen.navigation_transitions_favicon_size);
mNativeTabFavicon =
TabFaviconJni.get().init(TabFavicon.this, mNavigationTransitionsIdealFaviconSize);
}
@Override
public void initWebContents(WebContents webContents) {
TabFaviconJni.get().setWebContents(mNativeTabFavicon, TabFavicon.this, webContents);
}
@Override
public void cleanupWebContents(WebContents webContents) {
TabFaviconJni.get().resetWebContents(mNativeTabFavicon, TabFavicon.this);
}
@Override
public void destroyInternal() {
TabFaviconJni.get().onDestroyed(mNativeTabFavicon, TabFavicon.this);
}
/**
* @return The bitmap of the favicon scaled to 16x16dp. null if no favicon
* is specified or it requires the default favicon.
*/
private Bitmap getFavicon() {
// If we have no content or a native page, return null.
if (mTab.isNativePage() || mTab.getWebContents() == null) return null;
// Use the cached favicon only if the page wasn't changed.
if (mFavicon != null && mFaviconTabUrl != null && mFaviconTabUrl.equals(mTab.getUrl())) {
return mFavicon;
}
return TabFaviconJni.get().getFavicon(mNativeTabFavicon, TabFavicon.this);
}
/**
* @param currentWidth current favicon's width.
* @param currentHeight current favicon's height.
* @param width new favicon's width.
* @param height new favicon's height.
* @param idealFaviconSize the size of the ideal favicon (a square favicon).
* @return true iff the new favicon should replace the current one.
*/
private static boolean isBetterFavicon(
int currentWidth, int currentHeight, int width, int height, int idealFaviconSize) {
assert width >= 0 && height >= 0;
if (isIdealFaviconSize(idealFaviconSize, width, height)) return true;
// The page may be dynamically updating its URL, let it through.
if (currentWidth == width && currentHeight == height) return true;
// Prefer square favicons over rectangular ones
if (currentWidth != currentHeight && width == height) return true;
if (currentWidth == currentHeight && width != height) return false;
// Do not update favicon if it's already at least as big as the ideal size in both dimens
if (currentWidth >= idealFaviconSize && currentHeight >= idealFaviconSize) return false;
// Update favicon if the new one is larger in one dimen, but not smaller in the other
return (width > currentWidth && !(height < currentHeight))
|| (!(width < currentWidth) && height > currentHeight);
}
private static boolean isIdealFaviconSize(int idealFaviconSize, int width, int height) {
return width == idealFaviconSize && height == idealFaviconSize;
}
private boolean pageUrlChanged() {
GURL currentTabUrl = mTab.getUrl();
return !currentTabUrl.equals(mFaviconTabUrl);
}
private boolean pageUrlChangedForNavigationTransitions() {
GURL currentTabUrl = mTab.getUrl();
return !currentTabUrl.equals(mFaviconTabUrlForNavigationTransition);
}
@CalledByNative
@VisibleForTesting
void onFaviconAvailable(Bitmap icon, GURL iconUrl) {
assert icon != null;
// Bitmap#createScaledBitmap will return the original bitmap if it is already
// |mIdealFaviconSize|x|mIdealFaviconSize| DP.
mFavicon = Bitmap.createScaledBitmap(icon, mIdealFaviconSize, mIdealFaviconSize, true);
mFaviconWidth = icon.getWidth();
mFaviconHeight = icon.getHeight();
mFaviconTabUrl = mTab.getUrl();
RewindableIterator<TabObserver> observers = mTab.getTabObservers();
while (observers.hasNext()) observers.next().onFaviconUpdated(mTab, icon, iconUrl);
}
@CalledByNative
@VisibleForTesting
boolean shouldUpdateFaviconForBrowserUI(int newIconWidth, int newIconHeight) {
return pageUrlChanged()
|| isBetterFavicon(
mFaviconWidth,
mFaviconHeight,
newIconWidth,
newIconHeight,
mIdealFaviconSize);
}
@CalledByNative
private boolean shouldUpdateFaviconForNavigationTransitions(
int newIconWidth, int newIconHeight) {
boolean shouldUpdate =
pageUrlChangedForNavigationTransitions()
|| isBetterFavicon(
mNavigationTransitionsFaviconWidth,
mNavigationTransitionsFaviconHeight,
newIconWidth,
newIconHeight,
mNavigationTransitionsIdealFaviconSize);
if (shouldUpdate) {
mNavigationTransitionsFaviconWidth = newIconWidth;
mNavigationTransitionsFaviconHeight = newIconHeight;
mFaviconTabUrlForNavigationTransition = mTab.getUrl();
}
return shouldUpdate;
}
@NativeMethods
interface Natives {
long init(TabFavicon caller, int navigaionTransitionFaviconSize);
void onDestroyed(long nativeTabFavicon, TabFavicon caller);
void setWebContents(long nativeTabFavicon, TabFavicon caller, WebContents webContents);
void resetWebContents(long nativeTabFavicon, TabFavicon caller);
Bitmap getFavicon(long nativeTabFavicon, TabFavicon caller);
}
}
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