Page.java

package org.ebookdroid.core;

import org.ebookdroid.common.bitmaps.ByteBufferBitmap;
import org.ebookdroid.common.bitmaps.ByteBufferManager;
import org.ebookdroid.common.bitmaps.GLBitmaps;
import org.ebookdroid.common.settings.books.BookSettings;
import org.ebookdroid.common.settings.types.DocumentViewMode;
import org.ebookdroid.common.settings.types.PageType;
import org.ebookdroid.core.codec.CodecPageInfo;
import org.ebookdroid.core.codec.PageLink;
import org.ebookdroid.core.crop.PageCropper;
import org.ebookdroid.ui.viewer.IActivityController;

import android.graphics.Matrix;
import android.graphics.PointF;
import android.graphics.RectF;
import android.util.FloatMath;

import java.util.List;

import org.emdev.common.log.LogContext;
import org.emdev.common.log.LogManager;
import org.emdev.utils.MathUtils;
import org.emdev.utils.MatrixUtils;

public class Page {

    static final LogContext LCTX = LogManager.root().lctx("Page", false);

    public final PageIndex index;
    public final PageType type;
    public final CodecPageInfo cpi;

    final IActivityController base;
    public final PageTree nodes;

    RectF bounds;
    int aspectRatio;
    boolean recycled;
    float storedZoom;
    RectF zoomedBounds;

    int zoomLevel = 1;

    List<PageLink> links;

    public Page(final IActivityController base, final PageIndex index, final PageType pt, final CodecPageInfo cpi) {
        this.base = base;
        this.index = index;
        this.cpi = cpi;
        this.type = pt != null ? pt : PageType.FULL_PAGE;
        this.bounds = new RectF(0, 0, cpi.width / type.getWidthScale(), cpi.height);

        setAspectRatio(cpi);

        nodes = new PageTree(this);
    }

    public void recycle(final List<GLBitmaps> bitmapsToRecycle) {
        recycled = true;
        nodes.recycleAll(bitmapsToRecycle, true);
    }

    public float getAspectRatio() {
        return aspectRatio / 128.0f;
    }

    private boolean setAspectRatio(final float aspectRatio) {
        final int newAspectRatio = (int) Math.floor(aspectRatio * 128);
        if (this.aspectRatio != newAspectRatio) {
            this.aspectRatio = newAspectRatio;
            return true;
        }
        return false;
    }

    public boolean setAspectRatio(final CodecPageInfo page) {
        if (page != null) {
            return this.setAspectRatio(page.width / type.getWidthScale(), page.height);
        }
        return false;
    }

    public boolean setAspectRatio(final float width, final float height) {
        return setAspectRatio(width / height);
    }

    public void setBounds(final RectF pageBounds) {
        storedZoom = 0.0f;
        zoomedBounds = null;
        bounds = pageBounds;
    }

    public void setBounds(final float l, final float t, final float r, final float b) {
        if (bounds == null) {
            bounds = new RectF(l, t, r, b);
        } else {
            bounds.set(l, t, r, b);
        }
    }

    public boolean shouldCrop() {
        final BookSettings bs = base.getBookSettings();
        if (nodes.root.hasManualCropping()) {
            return true;
        }
        return bs != null && bs.cropPages;
    }

    public RectF getCropping() {
        return shouldCrop() ? nodes.root.getCropping() : null;
    }

    public RectF getCropping(PageTreeNode node) {
        return shouldCrop() ? node.getCropping() : null;
    }

    protected void updateAspectRatio() {
        final RectF cropping = getCropping();
        if (cropping != null) {
            final float pageWidth = cpi.width * cropping.width();
            final float pageHeight = cpi.height * cropping.height();
            setAspectRatio(pageWidth, pageHeight);
        } else {
            setAspectRatio(cpi);
        }
    }

    public RectF getBounds(final float zoom) {
        RectF bounds = new RectF();
        getBounds(zoom, bounds);
        return bounds;
    }

    public void getBounds(final float zoom, RectF target) {
        MathUtils.zoom(bounds, zoom, target);

        // If the unzoomed page fit on screen with room to spare, re-center the zoomed page
        // TODO: clarify these calculations
        final BookSettings bs = base.getBookSettings();
        if (bs != null && bs.viewMode == DocumentViewMode.SINGLE_PAGE) {
            if (bounds.left > 0) {
                target.offset((bounds.left + bounds.right) * (1 - zoom) / 2, 0);
            }
            if (bounds.top > 0) {
                target.offset(0, (bounds.top + bounds.bottom) * (1 - zoom) / 2);
            }
        }
    }

    public float getTargetRectScale() {
        return type.getWidthScale();
    }

    @Override
    public String toString() {
        final StringBuilder buf = new StringBuilder("Page");
        buf.append("[");

        buf.append("index").append("=").append(index);
        buf.append(", ");
        buf.append("bounds").append("=").append(bounds);
        buf.append(", ");
        buf.append("aspectRatio").append("=").append(aspectRatio);
        buf.append(", ");
        buf.append("type").append("=").append(type.name());
        buf.append("]");
        return buf.toString();
    }

    public static RectF getTargetRect(final PageType pageType, final RectF pageBounds, final RectF normalizedRect) {
        final Matrix tmpMatrix = MatrixUtils.get();

        tmpMatrix.postScale(pageBounds.width() * pageType.getWidthScale(), pageBounds.height());
        tmpMatrix.postTranslate(pageBounds.left - pageBounds.width() * pageType.getLeftPos(), pageBounds.top);

        final RectF targetRectF = new RectF();
        tmpMatrix.mapRect(targetRectF, normalizedRect);

        MathUtils.floor(targetRectF);

        return targetRectF;
    }

    public RectF getLinkSourceRect(final RectF pageBounds, final PageLink link) {
        if (link == null || link.sourceRect == null) {
            return null;
        }
        return getPageRegion(pageBounds, new RectF(link.sourceRect));
    }

    public RectF getPageRegion(final RectF pageBounds, final RectF sourceRect) {
        final RectF cb = getCropping();
        if (cb != null) {
            final Matrix m = MatrixUtils.get();
            final RectF psb = nodes.root.pageSliceBounds;
            m.postTranslate(psb.left - cb.left, psb.top - cb.top);
            m.postScale(psb.width() / cb.width(), psb.height() / cb.height());
            m.mapRect(sourceRect);
        }

        if (type == PageType.LEFT_PAGE && sourceRect.left >= 0.5f) {
            return null;
        }

        if (type == PageType.RIGHT_PAGE && sourceRect.right < 0.5f) {
            return null;
        }

        return getTargetRect(type, pageBounds, sourceRect);
    }

    protected RectF getColumn(final PointF pos) {
        final DecodeService ds = base.getDecodeService();
        final ByteBufferBitmap pageImage = ds.createPageThumbnail(PageCropper.BMP_SIZE, PageCropper.BMP_SIZE,
                index.docIndex, type.getInitialRect());

        final RectF column = PageCropper.getColumn(pageImage, pos.x, pos.y);
        ByteBufferManager.release(pageImage);

        return column;
    }
}