SelectionBoxHandler.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.tools;

import org.icepdf.ri.common.views.AbstractPageViewComponent;
import org.icepdf.ri.common.views.DocumentViewController;
import org.icepdf.ri.common.views.DocumentViewModel;
import org.icepdf.ri.common.views.PageViewComponentImpl;

import java.awt.*;
import java.awt.event.MouseEvent;

/**
 * Handles the drawing of a selection box commonly used for selection
 * type tools.
 *
 * @since 4.0
 */
public abstract class SelectionBoxHandler extends CommonToolHandler {

    // dashed selection rectangle stroke
    protected static float dash1[] = {1.0f};
    protected static BasicStroke stroke = new BasicStroke(1.0f,
            BasicStroke.CAP_BUTT,
            BasicStroke.JOIN_MITER,
            1.0f, dash1, 0.0f);

    // selection rectangle used for glyph intersection aka text selection
    protected Rectangle currentRect = null;
    protected Rectangle rectToDraw = null;
    protected Rectangle previousRectDrawn = new Rectangle();

    protected static Color selectionBoxColour = Color.lightGray;

    protected SelectionBoxHandler(DocumentViewController documentViewController,
                                  AbstractPageViewComponent pageViewComponent,
                                  DocumentViewModel documentViewModel) {
        super(documentViewController, pageViewComponent, documentViewModel);
    }

    public abstract void setSelectionRectangle(Point cursorLocation, Rectangle selection);

    public static void paintSelectionBox(Graphics g, Rectangle rectToDraw) {
        Graphics2D gg = (Graphics2D) g;
        Color oldColor = gg.getColor();
        Stroke oldStroke = gg.getStroke();
        if (rectToDraw != null) {
            //Draw a rectangle on top of the image.
            oldColor = g.getColor();
            gg.setColor(selectionBoxColour);
            gg.setStroke(stroke);
            gg.drawRect(rectToDraw.x, rectToDraw.y,
                    rectToDraw.width - 1, rectToDraw.height - 1);
            gg.setColor(oldColor);
        }

        gg.setColor(oldColor);
        gg.setStroke(oldStroke);
    }

    public void resetRectangle(int x, int y) {
        currentRect = new Rectangle(x, y, 0, 0);
    }

    public Rectangle getCurrentRect() {
        return currentRect;
    }

    public void setCurrentRect(Rectangle currentRect) {
        this.currentRect = currentRect;
    }

    public Rectangle getRectToDraw() {
        return rectToDraw;
    }

    public void setRectToDraw(Rectangle rectToDraw) {
        this.rectToDraw = rectToDraw;
    }

    public void clearRectangle(Component component) {
        // clear the rectangle
        currentRect = new Rectangle(0, 0, 0, 0);
        updateDrawableRect(component.getWidth(),
                component.getHeight());
    }

    /**
     * Update the size of the selection rectangle.
     *
     * @param x x-coordinate of the selection size update.
     * @param y y-coordinate of the selection size update.
     */
    public void updateSelectionSize(int x, int y, Component component) {
        // dragging across pages will result in null pointer if don't init.
        if (currentRect == null) {
            currentRect = new Rectangle(x, y, 0, 0);
        }
        currentRect.setSize(x - currentRect.x,
                y - currentRect.y);

        if (component != null) {
            updateDrawableRect(component.getWidth(), component.getHeight());
            Rectangle totalRepaint = rectToDraw.union(previousRectDrawn);
            component.repaint(totalRepaint.x, totalRepaint.y,
                    totalRepaint.width + 10, totalRepaint.height + 10);
        }
    }

    public void setSelectionSize(Rectangle rect, Component component) {

        currentRect = rect;

        updateDrawableRect(component.getWidth(), component.getHeight());
        Rectangle totalRepaint = rectToDraw.union(previousRectDrawn);
        component.repaint(totalRepaint.x, totalRepaint.y,
                totalRepaint.width, totalRepaint.height);
    }

    /**
     * Update the drawable rectangle so that it does not extend bast the edge
     * of the page.
     *
     * @param compWidth  width of component being selected
     * @param compHeight height of component being selected.
     */
    public void updateDrawableRect(int compWidth, int compHeight) {
        int x = currentRect.x;
        int y = currentRect.y;
        int width = currentRect.width;
        int height = currentRect.height;

        //Make the width and height positive, if necessary.
        if (width < 0) {
            width = 0 - width;
            x = x - width + 1;
            if (x < 0) {
                width += x;
                x = 0;
            }
        }
        if (height < 0) {
            height = 0 - height;
            y = y - height + 1;
            if (y < 0) {
                height += y;
                y = 0;
            }
        }

        //The rectangle shouldn't extend past the drawing area.
        if ((x + width) > compWidth) {
            width = compWidth - x;
        }
        if ((y + height) > compHeight) {
            height = compHeight - y;
        }

        //Update rectToDraw after saving old value.
        if (rectToDraw != null) {
            previousRectDrawn.setBounds(
                    rectToDraw.x, rectToDraw.y,
                    rectToDraw.width, rectToDraw.height);
            rectToDraw.setBounds(x, y, width, height);
        } else {
            rectToDraw = new Rectangle(x, y, width, height);
        }
    }

    /**
     * Utility method for determining if the mouse event occurred over a
     * page in the page view.
     *
     * @param e mouse event in this coordinates space
     * @return component that mouse event is over or null if not over a page.
     */
    protected PageViewComponentImpl isOverPageComponent(Container container, MouseEvent e) {
        // mouse -> page  broadcast .
        Component comp = container.findComponentAt(e.getPoint());
        if (comp instanceof PageViewComponentImpl) {
            return (PageViewComponentImpl) comp;
        } else {
            return null;
        }
    }
}