chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/OverlayPanelContent.java

// Copyright 2015 The Chromium Authors. All rights reserved.
// 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.compositor.bottombar;

import android.text.TextUtils;
import android.view.View;
import android.view.View.MeasureSpec;
import android.view.ViewGroup;
import android.view.ViewGroup.MarginLayoutParams;

import org.chromium.base.VisibleForTesting;
import org.chromium.base.annotations.CalledByNative;
import org.chromium.chrome.browser.ChromeActivity;
import org.chromium.chrome.browser.ChromeVersionInfo;
import org.chromium.chrome.browser.WebContentsFactory;
import org.chromium.chrome.browser.content.ContentUtils;
import org.chromium.chrome.browser.contextualsearch.ContextualSearchManager;
import org.chromium.chrome.browser.externalnav.ExternalNavigationHandler;
import org.chromium.chrome.browser.tab.Tab;
import org.chromium.components.embedder_support.delegate.WebContentsDelegateAndroid;
import org.chromium.components.embedder_support.view.ContentView;
import org.chromium.components.navigation_interception.InterceptNavigationDelegate;
import org.chromium.components.navigation_interception.NavigationParams;
import org.chromium.content_public.browser.LoadUrlParams;
import org.chromium.content_public.browser.RenderCoordinates;
import org.chromium.content_public.browser.WebContents;
import org.chromium.content_public.browser.WebContentsObserver;
import org.chromium.ui.base.ViewAndroidDelegate;

/**
 * Content container for an OverlayPanel. This class is responsible for the management of the
 * WebContents displayed inside of a panel and exposes a simple API relevant to actions a
 * panel has.
 */
public class OverlayPanelContent {

    /** The WebContents that this panel will display. */
    private WebContents mWebContents;

    /** The container view that this panel uses. */
    private ViewGroup mContainerView;

    /** The pointer to the native version of this class. */
    private long mNativeOverlayPanelContentPtr;

    /** Used for progress bar events. */
    private final WebContentsDelegateAndroid mWebContentsDelegate;

    /** The activity that this content is contained in. */
    private ChromeActivity mActivity;

    /** Observer used for tracking loading and navigation. */
    private WebContentsObserver mWebContentsObserver;

    /** The URL that was directly loaded using the {@link #loadUrl(String)} method. */
    private String mLoadedUrl;

    /** Whether the content has started loading a URL. */
    private boolean mDidStartLoadingUrl;

    /**
     * Whether we should reuse any existing WebContents instead of deleting and recreating.
     * See crbug.com/682953 for details.
     */
    private boolean mShouldReuseWebContents;

    /**
     * Whether the WebContents is processing a pending navigation.
     * NOTE(pedrosimonetti): This is being used to prevent redirections on the SERP to be
     * interpreted as a regular navigation, which should cause the Contextual Search Panel
     * to be promoted as a Tab. This was added to work around a server bug that has been fixed.
     * Just checking for whether the Content has been touched is enough to determine whether a
     * navigation should be promoted (assuming it was caused by the touch), as done in
     * {@link ContextualSearchManager#shouldPromoteSearchNavigation()}.
     * For more details, see crbug.com/441048
     * TODO(pedrosimonetti): remove this from M48 or move it to Contextual Search Panel.
     */
    private boolean mIsProcessingPendingNavigation;

    /** Whether the content view is currently being displayed. */
    private boolean mIsContentViewShowing;

    /** The observer used by this object to inform implementers of different events. */
    private OverlayContentDelegate mContentDelegate;

    /** Used to observe progress bar events. */
    private OverlayContentProgressObserver mProgressObserver;

    /** If a URL is set to delayed load (load on user interaction), it will be stored here. */
    private String mPendingUrl;

    // http://crbug.com/522266 : An instance of InterceptNavigationDelegateImpl should be kept in
    // java layer. Otherwise, the instance could be garbage-collected unexpectedly.
    private InterceptNavigationDelegate mInterceptNavigationDelegate;

    /** Set to {@code True} if opened for an incognito tab. */
    private boolean mIsIncognito;

    /** The desired size of the {@link ContentView} associated with this panel content. */
    private int mContentViewWidth;
    private int mContentViewHeight;
    private boolean mSubtractBarHeight;

    /** The height of the bar at the top of the OverlayPanel in pixels. */
    private final int mBarHeightPx;

    /** Sets the top offset of the overlay panel in pixel. 0 when fully expanded. */
    private int mPanelTopOffsetPx;

    private class OverlayViewDelegate extends ViewAndroidDelegate {
        public OverlayViewDelegate(ViewGroup v) {
            super(v);
        }

        @Override
        public void setViewPosition(View view, float x, float y, float width, float height,
                int leftMargin, int topMargin) {
            super.setViewPosition(view, x, y, width, height, leftMargin, topMargin);

            // Applies top offset depending on the overlay panel state.
            MarginLayoutParams lp = (MarginLayoutParams) view.getLayoutParams();
            lp.topMargin += mPanelTopOffsetPx + mBarHeightPx;
        }
    }

    // ============================================================================================
    // InterceptNavigationDelegateImpl
    // ============================================================================================

    // Used to intercept intent navigations.
    // TODO(jeremycho): Consider creating a Tab with the Panel's WebContents.
    // which would also handle functionality like long-press-to-paste.
    private class InterceptNavigationDelegateImpl implements InterceptNavigationDelegate {
        final ExternalNavigationHandler mExternalNavHandler;

        public InterceptNavigationDelegateImpl() {
            Tab tab = mActivity.getActivityTab();
            mExternalNavHandler = (tab != null && tab.getWebContents() != null)
                    ? new ExternalNavigationHandler(tab)
                    : null;
        }

        @Override
        public boolean shouldIgnoreNavigation(NavigationParams navigationParams) {
            // If either of the required params for the delegate are null, do not call the
            // delegate and ignore the navigation.
            if (mExternalNavHandler == null || navigationParams == null) return true;
            // TODO(mdjones): Rather than passing the two navigation params, instead consider
            // passing a boolean to make this API simpler.
            return !mContentDelegate.shouldInterceptNavigation(mExternalNavHandler,
                    navigationParams);
        }
    }

    // ============================================================================================
    // Constructor
    // ============================================================================================

    /**
     * @param contentDelegate An observer for events that occur on this content. If null is passed
     *                        for this parameter, the default one will be used.
     * @param progressObserver An observer for progress related events.
     * @param activity The ChromeActivity that contains this object.
     * @param isIncognito {@True} if opened for an incognito tab
     * @param barHeight The height of the bar at the top of the OverlayPanel in dp.
     */
    public OverlayPanelContent(OverlayContentDelegate contentDelegate,
            OverlayContentProgressObserver progressObserver, ChromeActivity activity,
            boolean isIncognito, float barHeight) {
        mNativeOverlayPanelContentPtr = nativeInit();
        mContentDelegate = contentDelegate;
        mProgressObserver = progressObserver;
        mActivity = activity;
        mIsIncognito = isIncognito;
        mBarHeightPx = (int) (barHeight * mActivity.getResources().getDisplayMetrics().density);

        mWebContentsDelegate = new WebContentsDelegateAndroid() {
            private boolean mIsFullscreen;

            @Override
            public void loadingStateChanged(boolean toDifferentDocument) {
                boolean isLoading = mWebContents != null && mWebContents.isLoading();
                if (isLoading) {
                    mProgressObserver.onProgressBarStarted();
                } else {
                    mProgressObserver.onProgressBarFinished();
                }
            }

            @Override
            public void onLoadProgressChanged(int progress) {
                mProgressObserver.onProgressBarUpdated(progress);
            }

            @Override
            public void enterFullscreenModeForTab(boolean prefersNavigationBar) {
                mIsFullscreen = true;
            }

            @Override
            public void exitFullscreenModeForTab() {
                mIsFullscreen = false;
            }

            @Override
            public boolean isFullscreenForTabOrPending() {
                return mIsFullscreen;
            }

            @Override
            public int getTopControlsHeight() {
                return (int) (mBarHeightPx
                        / mActivity.getWindowAndroid().getDisplay().getDipScale());
            }

            @Override
            public int getBottomControlsHeight() {
                return 0;
            }

            @Override
            public boolean controlsResizeView() {
                return false;
            }
        };
    }

    // ============================================================================================
    // WebContents related
    // ============================================================================================

    /**
     * Load a URL; this will trigger creation of a new WebContents if being loaded immediately,
     * otherwise one is created when the panel's content becomes visible.
     * @param url The URL that should be loaded.
     * @param shouldLoadImmediately If a URL should be loaded immediately or wait until visibility
     *        changes.
     */
    public void loadUrl(String url, boolean shouldLoadImmediately) {
        mPendingUrl = null;

        if (!shouldLoadImmediately) {
            mPendingUrl = url;
        } else {
            createNewWebContents();
            mLoadedUrl = url;
            mDidStartLoadingUrl = true;
            mIsProcessingPendingNavigation = true;
            mWebContents.getNavigationController().loadUrl(new LoadUrlParams(url));
        }
    }

    /**
     * Call this when a loadUrl request has failed to notify the panel that the WebContents can
     * be reused.  See crbug.com/682953 for details.
     */
    void onLoadUrlFailed() {
        mShouldReuseWebContents = true;
    }

    /**
     * Set the desired size of the underlying {@link ContentView}. This is determined
     * by the {@link OverlayPanel} before the creation of the content view.
     * @param width The width of the content view.
     * @param height The height of the content view.
     * @param subtractBarHeight if {@code true} view height should be smaller by {@code mBarHeight}.
     */
    void setContentViewSize(int width, int height, boolean subtractBarHeight) {
        mContentViewWidth = width;
        mContentViewHeight = height;
        mSubtractBarHeight = subtractBarHeight;
    }

    /**
     * Makes the content visible, causing it to be rendered.
     */
    public void showContent() {
        setVisibility(true);
    }

    /**
     * Sets the top offset of the overlay panel that varies as the panel state changes.
     * @param offset Top offset in pixel.
     */
    public void setPanelTopOffset(int offset) {
        mPanelTopOffsetPx = offset;
    }

    /**
     * Create a new WebContents that will be managed by this panel.
     */
    private void createNewWebContents() {
        if (mWebContents != null) {
            // If the WebContents has already been created, but never used,
            // then there's no need to create a new one.
            if (!mDidStartLoadingUrl || mShouldReuseWebContents) return;

            destroyWebContents();
        }

        // Creates an initially hidden WebContents which gets shown when the panel is opened.
        mWebContents = WebContentsFactory.createWebContents(mIsIncognito, true);

        ContentView cv = ContentView.createContentView(mActivity, mWebContents);
        if (mContentViewWidth != 0 || mContentViewHeight != 0) {
            int width = mContentViewWidth == 0 ? ContentView.DEFAULT_MEASURE_SPEC
                    : MeasureSpec.makeMeasureSpec(mContentViewWidth, MeasureSpec.EXACTLY);
            int height = mContentViewHeight == 0 ? ContentView.DEFAULT_MEASURE_SPEC
                    : MeasureSpec.makeMeasureSpec(mContentViewHeight, MeasureSpec.EXACTLY);
            cv.setDesiredMeasureSpec(width, height);
        }

        OverlayViewDelegate delegate = new OverlayViewDelegate(cv);
        mWebContents.initialize(ChromeVersionInfo.getProductVersion(), delegate, cv,
                mActivity.getWindowAndroid(), WebContents.createDefaultInternalsHolder());
        ContentUtils.setUserAgentOverride(mWebContents);

        // Transfers the ownership of the WebContents to the native OverlayPanelContent.
        nativeSetWebContents(mNativeOverlayPanelContentPtr, mWebContents, mWebContentsDelegate);

        mWebContentsObserver =
                new WebContentsObserver(mWebContents) {
                    @Override
                    public void didStartLoading(String url) {
                        mContentDelegate.onContentLoadStarted(url);
                    }

                    @Override
                    public void navigationEntryCommitted() {
                        mContentDelegate.onNavigationEntryCommitted();
                    }

                    @Override
                    public void didStartNavigation(String url, boolean isInMainFrame,
                            boolean isSameDocument, long navigationHandleProxy) {
                        if (isInMainFrame && !isSameDocument) {
                            mContentDelegate.onMainFrameLoadStarted(
                                    url, !TextUtils.equals(url, mLoadedUrl));
                        }
                    }

                    @Override
                    public void didFinishNavigation(String url, boolean isInMainFrame,
                            boolean isErrorPage, boolean hasCommitted, boolean isSameDocument,
                            boolean isFragmentNavigation, boolean isRendererInitiated,
                            boolean isDownload, Integer pageTransition, int errorCode,
                            String errorDescription, int httpStatusCode) {
                        if (hasCommitted && isInMainFrame) {
                            mIsProcessingPendingNavigation = false;
                            mContentDelegate.onMainFrameNavigation(url,
                                    !TextUtils.equals(url, mLoadedUrl),
                                    isHttpFailureCode(httpStatusCode));
                        }
                    }
                };

        mContainerView = cv;
        mInterceptNavigationDelegate = new InterceptNavigationDelegateImpl();
        nativeSetInterceptNavigationDelegate(
                mNativeOverlayPanelContentPtr, mInterceptNavigationDelegate, mWebContents);

        mContentDelegate.onContentViewCreated();
        resizePanelContentView();
        mActivity.getCompositorViewHolder().addView(mContainerView, 1);
    }

    /**
     * Destroy this panel's WebContents.
     */
    private void destroyWebContents() {
        if (mWebContents != null) {
            // Native destroy will call up to destroy the Java WebContents.
            nativeDestroyWebContents(mNativeOverlayPanelContentPtr);
            mWebContents = null;
            if (mWebContentsObserver != null) {
                mWebContentsObserver.destroy();
                mWebContentsObserver = null;
            }

            mDidStartLoadingUrl = false;
            mIsProcessingPendingNavigation = false;
            mShouldReuseWebContents = false;

            setVisibility(false);

            // After everything has been disposed, notify the observer.
            mContentDelegate.onContentViewDestroyed();
        }
    }

    // ============================================================================================
    // Utilities
    // ============================================================================================

    /**
     * Calls updateBrowserControlsState on the WebContents.
     * @param areControlsHidden Whether the browser controls are hidden for the web contents. If
     *                          false, the web contents viewport always accounts for the controls.
     *                          Otherwise the web contents never accounts for them.
     */
    public void updateBrowserControlsState(boolean areControlsHidden) {
        nativeUpdateBrowserControlsState(mNativeOverlayPanelContentPtr, areControlsHidden);
    }

    /**
     * @return Whether a pending navigation if being processed.
     */
    public boolean isProcessingPendingNavigation() {
        return mIsProcessingPendingNavigation;
    }

    /**
     * Reset the content's scroll position to (0, 0).
     */
    public void resetContentViewScroll() {
        if (mWebContents != null) {
            mWebContents.getEventForwarder().scrollTo(0, 0);
        }
    }

    /**
     * @return The Y scroll position.
     */
    public float getContentVerticalScroll() {
        return mWebContents != null
                ? RenderCoordinates.fromWebContents(mWebContents).getScrollYPixInt()
                : -1.f;
    }

    /**
     * Sets the visibility of the Search Content View.
     * @param isVisible True to make it visible.
     */
    private void setVisibility(boolean isVisible) {
        if (mIsContentViewShowing == isVisible) return;

        mIsContentViewShowing = isVisible;

        if (isVisible) {
            // If the last call to loadUrl was specified to be delayed, load it now.
            if (!TextUtils.isEmpty(mPendingUrl)) loadUrl(mPendingUrl, true);

            // The WebContents is created with the search request, but if none was made we'll need
            // one in order to display an empty panel.
            if (mWebContents == null) createNewWebContents();

            // NOTE(pedrosimonetti): Calling onShow() on the WebContents will cause the page
            // to be rendered. This has a side effect of causing the page to be included in
            // your Web History (if enabled). For this reason, onShow() should only be called
            // when we know for sure the page will be seen by the user.
            if (mWebContents != null) mWebContents.onShow();

            mContentDelegate.onContentViewSeen();
        } else {
            if (mWebContents != null) mWebContents.onHide();
        }

        mContentDelegate.onVisibilityChanged(isVisible);
    }

    /**
     * @return Whether the given HTTP result code represents a failure or not.
     */
    private static boolean isHttpFailureCode(int httpResultCode) {
        return httpResultCode <= 0 || httpResultCode >= 400;
    }

    /**
     * @return true if the content is visible on the page.
     */
    public boolean isContentShowing() {
        return mIsContentViewShowing;
    }

    // ============================================================================================
    // Methods for managing this panel's WebContents.
    // ============================================================================================

    /**
     * Reset this object's native pointer to 0;
     */
    @CalledByNative
    private void clearNativePanelContentPtr() {
        assert mNativeOverlayPanelContentPtr != 0;
        mNativeOverlayPanelContentPtr = 0;
    }

    protected WebContents getWebContents() {
        return mWebContents;
    }

    ViewGroup getContainerView() {
        return mContainerView;
    }

    void resizePanelContentView() {
        WebContents webContents = getWebContents();
        if (webContents == null) return;
        int viewHeight = mContentViewHeight - (mSubtractBarHeight ? mBarHeightPx : 0);
        nativeOnPhysicalBackingSizeChanged(
                mNativeOverlayPanelContentPtr, webContents, mContentViewWidth, viewHeight);
        mWebContents.setSize(mContentViewWidth, viewHeight);
    }

    /**
     * Remove the list history entry from this panel if it was within a certain timeframe.
     * @param historyUrl The URL to remove.
     * @param urlTimeMs The time the URL was navigated to.
     */
    public void removeLastHistoryEntry(String historyUrl, long urlTimeMs) {
        nativeRemoveLastHistoryEntry(mNativeOverlayPanelContentPtr, historyUrl, urlTimeMs);
    }

    /**
     * Destroy the native component of this class.
     */
    @VisibleForTesting
    public void destroy() {
        if (mWebContents != null) destroyWebContents();

        // Tests will not create the native pointer, so we need to check if it's not zero
        // otherwise calling nativeDestroy with zero will make Chrome crash.
        if (mNativeOverlayPanelContentPtr != 0L) {
            nativeDestroy(mNativeOverlayPanelContentPtr);
        }
    }

    // Native calls.
    private native long nativeInit();
    private native void nativeDestroy(long nativeOverlayPanelContent);
    private native void nativeRemoveLastHistoryEntry(
            long nativeOverlayPanelContent, String historyUrl, long urlTimeMs);
    private native void nativeOnPhysicalBackingSizeChanged(
            long nativeOverlayPanelContent, WebContents webContents, int width, int height);
    private native void nativeSetWebContents(long nativeOverlayPanelContent,
            WebContents webContents, WebContentsDelegateAndroid delegate);
    private native void nativeDestroyWebContents(long nativeOverlayPanelContent);
    private native void nativeSetInterceptNavigationDelegate(long nativeOverlayPanelContent,
            InterceptNavigationDelegate delegate, WebContents webContents);
    private native void nativeUpdateBrowserControlsState(
            long nativeOverlayPanelContent, boolean areControlsHidden);
}