chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/readermode/ReaderModePanel.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.readermode;

import android.content.Context;

import org.chromium.chrome.R;
import org.chromium.chrome.browser.compositor.bottombar.OverlayContentDelegate;
import org.chromium.chrome.browser.compositor.bottombar.OverlayContentProgressObserver;
import org.chromium.chrome.browser.compositor.bottombar.OverlayPanel;
import org.chromium.chrome.browser.compositor.bottombar.OverlayPanel.StateChangeReason;
import org.chromium.chrome.browser.compositor.bottombar.OverlayPanelContent;
import org.chromium.chrome.browser.compositor.bottombar.OverlayPanelContentViewDelegate;
import org.chromium.chrome.browser.compositor.bottombar.OverlayPanelManager;
import org.chromium.chrome.browser.compositor.bottombar.OverlayPanelManager.PanelPriority;
import org.chromium.chrome.browser.compositor.layouts.LayoutUpdateHost;
import org.chromium.chrome.browser.compositor.scene_layer.ContextualSearchSceneLayer;
import org.chromium.chrome.browser.compositor.scene_layer.SceneLayer;
import org.chromium.chrome.browser.dom_distiller.ReaderModeManagerDelegate;
import org.chromium.content.browser.ContentViewCore;
import org.chromium.ui.resources.ResourceManager;

/**
 * The panel containing reader mode.
 */
public class ReaderModePanel extends OverlayPanel {

    /**
     * The compositor layer used for drawing the panel.
     */
    private ContextualSearchSceneLayer mSceneLayer;

    /**
     * Delegate for calling functions on the ReaderModeManager.
     */
    private ReaderModeManagerDelegate mManagerDelegate;

    /**
     * Delegate for passing the current ContentViewCore to the layout manager.
     */
    private OverlayPanelContentViewDelegate mContentViewDelegate;

    /**
     * The opacity of the panel bar text.
     */
    private float mReaderBarTextOpacity;

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

    /**
     * @param context The current Android {@link Context}.
     * @param updateHost The {@link LayoutUpdateHost} used to request updates in the Layout.
     */
    public ReaderModePanel(Context context, LayoutUpdateHost updateHost,
                OverlayPanelManager panelManager,
                OverlayPanelContentViewDelegate contentViewDelegate) {
        super(context, updateHost, panelManager);
        mSceneLayer = createNewReaderModeSceneLayer();
        mContentViewDelegate = contentViewDelegate;
    }

    /**
     * Destroy the panel's components.
     */
    public void destroy() {
        super.destroy();
        destroyReaderModeBarControl();
    }

    @Override
    public OverlayPanelContent createNewOverlayPanelContent() {
        OverlayContentDelegate delegate = new OverlayContentDelegate() {
            @Override
            public void onContentViewCreated(ContentViewCore contentView) {
                mContentViewDelegate.setOverlayPanelContentViewCore(contentView);
            }

            @Override
            public void onContentViewDestroyed() {
                mContentViewDelegate.releaseOverlayPanelContentViewCore();
            }

            @Override
            public void onMainFrameNavigation(String url, boolean isExternalUrl,
                    boolean isFailure) {
                if (isExternalUrl) {
                    mManagerDelegate.createNewTab(url);
                }
            }
        };

        return new OverlayPanelContent(delegate, new OverlayContentProgressObserver(), mActivity);
    }

    // ============================================================================================
    // Scene layer
    // ============================================================================================

    @Override
    public SceneLayer getSceneLayer() {
        return mSceneLayer;
    }

    @Override
    public void updateSceneLayer(ResourceManager resourceManager) {
        if (mSceneLayer == null) return;

        // This will cause the ContentViewCore to size itself appropriately for the panel (includes
        // top controls height).
        updateTopControlsState();

        // TODO(mdjones): Uncomment this when other changes have merged!
        //mSceneLayer.update(resourceManager, this,
        //    0, getBarTextViewId(), null, 0, mReaderBarTextOpacity, null);
    }

    /**
     * Create a new scene layer for this panel. This should be overridden by tests as necessary.
     */
    protected ContextualSearchSceneLayer createNewReaderModeSceneLayer() {
        return new ContextualSearchSceneLayer(mContext.getResources().getDisplayMetrics().density);
    }

    // ============================================================================================
    // Manager Integration
    // ============================================================================================

    /**
     * Sets the {@code ReaderModeManagerDelegate} associated with this panel.
     * @param delegate The {@code ReaderModeManagerDelegate}.
     */
    public void setManagerDelegate(ReaderModeManagerDelegate delegate) {
        // TODO(mdjones): This looks similar to setManagementDelegate in ContextualSearchPanel,
        // consider moving this to OverlayPanel.
        if (mManagerDelegate != delegate) {
            mManagerDelegate = delegate;
            if (mManagerDelegate != null) {
                setChromeActivity(mManagerDelegate.getChromeActivity());
                initializeUiState();
                updateBasePageTargetY();
            }
        }
    }

    // ============================================================================================
    // Generic Event Handling
    // ============================================================================================

    @Override
    public void handleBarClick(long time, float x, float y) {
        super.handleBarClick(time, x, y);
        if (isCoordinateInsideCloseButton(x, y)) {
            closePanel(StateChangeReason.CLOSE_BUTTON, true);
            mManagerDelegate.onCloseButtonPressed();
        } else {
            maximizePanel(StateChangeReason.SEARCH_BAR_TAP);
        }
    }

    @Override
    public boolean onInterceptBarClick() {
        // TODO(mdjones): Handle compatibility mode here (promote to tab on tap).
        return false;
    }

    // ============================================================================================
    // Panel base methods
    // ============================================================================================

    @Override
    public PanelPriority getPriority() {
        return PanelPriority.MEDIUM;
    }

    @Override
    public boolean canBeSuppressed() {
        return true;
    }

    @Override
    public void peekPanel(StateChangeReason reason) {
        super.peekPanel(reason);
        mManagerDelegate.onPanelPeek();
    }

    @Override
    protected void updatePanelForCloseOrPeek(float percent) {
        super.updatePanelForCloseOrPeek(percent);
        getReaderModeBarControl().setBarText(R.string.reader_view_text);
        mReaderBarTextOpacity = 1.0f;
    }

    @Override
    protected void updatePanelForExpansion(float percent) {
        super.updatePanelForExpansion(percent);
        if (percent < 0.5f) {
            mReaderBarTextOpacity = 1.0f - 2.0f * percent;
            getReaderModeBarControl().setBarText(R.string.reader_view_text);
        } else {
            mReaderBarTextOpacity = 2.0f * (percent - 0.5f);
            getReaderModeBarControl().setBarText(R.string.reader_mode_expanded_title);
        }
    }

    @Override
    protected void updatePanelForMaximization(float percent) {
        super.updatePanelForMaximization(percent);
        getReaderModeBarControl().setBarText(R.string.reader_mode_expanded_title);
        mReaderBarTextOpacity = 1.0f;
    }

    @Override
    public float getArrowIconOpacity() {
        // TODO(mdjones): This will not be needed once Reader Mode has its own scene layer.
        // Never show the arrow icon.
        return 0.0f;
    }

    @Override
    public float getCloseIconOpacity() {
        // TODO(mdjones): Make close button controlled by overlay panel as a toggle.
        // TODO(mdjones): This will not be needed once Reader Mode has its own scene layer.
        // Always show the close icon.
        return 1.0f;
    }

    @Override
    protected float calculateBasePageTargetY(PanelState state) {
        // TODO(mdjones): Remove this method when this panel behaves like the toolbar. In the case
        // of reader mode the base page will always need to move the same amount.
        return -getToolbarHeight();
    }

    // ============================================================================================
    // ReaderModeBarControl
    // ============================================================================================

    private ReaderModeBarControl mReaderModeBarControl;

    /**
     * @return The Id of the Search Term View.
     */
    public int getBarTextViewId() {
        return getReaderModeBarControl().getViewId();
    }

    /**
     * Creates the ReaderModeBarControl, if needed. The Views are set to INVISIBLE, because
     * they won't actually be displayed on the screen (their snapshots will be displayed instead).
     */
    protected ReaderModeBarControl getReaderModeBarControl() {
        assert mContainerView != null;
        assert mResourceLoader != null;

        if (mReaderModeBarControl == null) {
            mReaderModeBarControl =
                    new ReaderModeBarControl(this, mContext, mContainerView, mResourceLoader);
        }

        assert mReaderModeBarControl != null;
        return mReaderModeBarControl;
    }

    /**
     * Destroys the ReaderModeBarControl.
     */
    protected void destroyReaderModeBarControl() {
        if (mReaderModeBarControl != null) {
            mReaderModeBarControl.destroy();
            mReaderModeBarControl = null;
        }
    }
}