OnePageView.java

/*
 * Copyright 2006-2017 ICEsoft Technologies Canada Corp.
 *
 * 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 org.icepdf.ri.common.views;

import org.icepdf.ri.common.KeyListenerPageChanger;
import org.icepdf.ri.common.MouseWheelListenerPageChanger;
import org.icepdf.ri.common.SwingController;

import javax.swing.*;
import java.awt.*;

/**
 * <p>Constructs a one  page view as defined in the PDF specification. A one
 * page view displays one page at a time.</p>
 * <br>
 * <p>Page views are basic containers which use Swing Layout Containers to
 * place pages </p>
 *
 * @since 2.5
 */
@SuppressWarnings("serial")
public class OnePageView extends AbstractDocumentView {

    protected Object pageChangerListener;

    protected KeyListenerPageChanger keyListenerPageChanger;


    public OnePageView(DocumentViewController documentDocumentViewController,
                       JScrollPane documentScrollpane,
                       DocumentViewModel documentViewModel) {

        super(documentDocumentViewController, documentScrollpane, documentViewModel);

        // used to redirect mouse events
        this.documentScrollpane = documentScrollpane;

        // put all the gui elements together
        buildGUI();

        // add page changing key listeners
        if (this.documentViewController.getParentController() instanceof SwingController) {
            pageChangerListener =
                    MouseWheelListenerPageChanger.install(
                            (SwingController) this.documentViewController.getParentController(),
                            this.documentScrollpane, this);

            keyListenerPageChanger =
                    KeyListenerPageChanger.install(
                            (SwingController) this.documentViewController.getParentController(),
                            this.documentScrollpane, this);
        }

    }

    private void buildGUI() {
        // add all page components to gridlayout panel
        pagesPanel = new JPanel();
        pagesPanel.setBackground(BACKGROUND_COLOUR);
        // one column equals single page view continuous
        GridLayout gridLayout = new GridLayout(0, 1, horizontalSpace, verticalSpace);
        pagesPanel.setLayout(gridLayout);

        // use a gridBag to center the page component panel
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.weighty = 1.0;                  // allows vertical resizing
        gbc.weightx = 1.0;                  // allows horizontal resizing
        gbc.insets =  // component spacer [top, left, bottom, right]
                new Insets(layoutInserts, layoutInserts, layoutInserts, layoutInserts);
        gbc.gridwidth = GridBagConstraints.REMAINDER;      // one component per row

        // finally add all the components
        // add components for every page in the document
        updateDocumentView();

        this.setLayout(new GridBagLayout());
        this.add(pagesPanel, gbc);

    }

    public void updateDocumentView() {

        java.util.List<AbstractPageViewComponent> pageComponents =
                documentViewModel.getPageComponents();

        if (pageComponents != null) {

            PageViewComponent pageViewComponent =
                    pageComponents.get(documentViewModel.getViewCurrentPageIndex());
            if (pageViewComponent != null) {

                // remove old component
                pagesPanel.removeAll();

                pageViewComponent.setDocumentViewCallback(this);
                // add component to layout
                pagesPanel.add(new PageViewDecorator(
                        (AbstractPageViewComponent) pageViewComponent));
                ((AbstractPageViewComponent) pageViewComponent).validate();
            }

            // make sure we have setup all pages with callback call.
            for (PageViewComponent pageViewCom : pageComponents) {
                if (pageViewCom != null) {
                    pageViewCom.setDocumentViewCallback(this);
                }
            }
        }
    }

    /**
     * Returns a next page increment of one.
     */
    public int getNextPageIncrement() {
        return 1;
    }

    /**
     * Returns a previous page increment of one.
     */
    public int getPreviousPageIncrement() {
        return 1;
    }

    public void dispose() {
        disposing = true;
        // remove utilities
        if (pageChangerListener != null) {
            MouseWheelListenerPageChanger.uninstall(documentScrollpane,
                    pageChangerListener);
        }
        if (keyListenerPageChanger != null) {
            keyListenerPageChanger.uninstall();
        }

        // trigger a re-layout
        pagesPanel.removeAll();
        pagesPanel.invalidate();

        // make sure we call super.
        super.dispose();
    }

    public Dimension getDocumentSize() {
        float pageViewWidth = 0;
        float pageViewHeight = 0;
        if (pagesPanel != null) {
            int count = pagesPanel.getComponentCount();
            Component comp;
            // should only have one page view decorator for single page view.
            for (int i = 0; i < count; i++) {
                comp = pagesPanel.getComponent(i);
                if (comp instanceof PageViewDecorator) {
                    PageViewDecorator pvd = (PageViewDecorator) comp;
                    Dimension dim = pvd.getPreferredSize();
                    pageViewWidth = dim.width;
                    pageViewHeight = dim.height;
                    break;
                }
            }
        }
        // normalize the dimensions to a zoom level of zero. 
        float currentZoom = documentViewModel.getViewZoom();
        pageViewWidth = Math.abs(pageViewWidth / currentZoom);
        pageViewHeight = Math.abs(pageViewHeight / currentZoom);

        // add any horizontal padding from layout manager
        pageViewWidth += AbstractDocumentView.horizontalSpace * 2;
        pageViewHeight += AbstractDocumentView.verticalSpace * 2;
        return new Dimension((int) pageViewWidth, (int) pageViewHeight);
    }

    public void paintComponent(Graphics g) {
        Rectangle clipBounds = g.getClipBounds();
        // paint background gray
        g.setColor(BACKGROUND_COLOUR);
        g.fillRect(clipBounds.x, clipBounds.y, clipBounds.width, clipBounds.height);
        // paint selection box
        super.paintComponent(g);
    }
}