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TestChart.javaAPI DocJ2ME MIDP 2.05117Thu Nov 07 12:02:18 GMT 2002example.photoalbum

TestChart

public class TestChart extends Object
A quick sample of graphics which generates a series of images that can be used as a sample animation. The animation consists of a title, a pie, and a bar chart. The charts are sized to the requested size so they will look good on devices with various screen sizes.

Fields Summary
int
w
Width of the canvas
int
h
Height of the canvas
Font
font
Font used for drawing text
int
fh
height of the font
int
titleHeight
Height of the title
int
pad
Padding used between items
int
pieSize
Size of the Pie chart used for width and height
int
barSize
Size of the Bar chart used for width and height
int
frameno
The current frame number
Constructors Summary
public TestChart(int width, int height)
Initialize a new TestPattern to match the requested size.

param
width the requested width of the Images
param
height the requested height of the Images

        w = width;
        h = height;
        font = Font.getFont(Font.FACE_SYSTEM,
			    Font.STYLE_PLAIN, Font.SIZE_SMALL);
        fh = font.getHeight();

        /*
	 * Compute the sizes of the bar and pie charts
	 * It should use all the space except for the title and event regions
	 * Don't let the charts get too small
	 */
        pad = 2;
        titleHeight = fh + pad * 2;
        barSize = h - (titleHeight + pad);
        if (barSize < 10)               // Don't let them get too small
            barSize = 10;
        if (barSize > (w - pad) / 2)    // Shrink to 1/2 width
            barSize = (w - pad) / 2;
        pieSize = barSize;
Methods Summary
public java.util.VectorgenerateImages()
Generate the frames for this animated chart. It consists of hour frames with the first frame containing only the base, and frame 2,3,4 adding the colors to the bars of the bar chart.

return
the Vector of Images.

        Vector v = new Vector(4);
        for (frameno = 0; frameno < 4; frameno++) {
            Image image = Image.createImage(w, h);
            paint(image.getGraphics());
            v.addElement(image);
        }
        return v;
public voidpaint(Graphics g)
Draw the current frame. The field frameno contains the current frame number.

param
g the Graphics context

        g.setFont(font);
        g.setGrayScale(255);
        g.fillRect(0, 0, w, h);

        // Draw Fill and outline for background of title Text
        int swidth = pad * 2 + font.stringWidth("Chart Samples");
        int title_x = (w - swidth)/2;

        g.setGrayScale(128);
        g.fillRoundRect(title_x, 0, swidth, fh, 5, 5);
        g.setGrayScale(0);
        g.drawRoundRect(title_x, 0, swidth, fh, 5, 5);

        // Sample Text
        g.setColor(0, 0, 0);
        g.drawString("Chart Samples", 
		     title_x + pad, pad, Graphics.TOP|Graphics.LEFT);

        g.translate(0, titleHeight + pad);    // Translate to below title text

        // Draw pie chart on the left using the barSize for width and height
        g.setColor(255, 0, 0);
        g.fillArc(0, 0, pieSize, pieSize, 45, 270);
        g.setColor(0, 255, 0);
        g.fillArc(0, 0, pieSize, pieSize, 0, 45);
        g.setColor(0, 0, 255);
        g.fillArc(0, 0, pieSize, pieSize, 0, -45);
        g.setColor(0);
        g.drawArc(0, 0, pieSize, pieSize, 0, 360);

        // Draw Bar chart on right side of the display
        // scale the values to the pieSize maximum value
        int yorig = barSize;
        int h1 = barSize / 3, h2 = barSize / 2, h3 = barSize;
        int avg = (h1 + h2 + h3) / 3;

        // Move over to draw Bar chart
        g.translate((w + pad) / 2, 0);

        int bw = pieSize / 7;
        if (bw < 2)
             bw = 2;
        if (frameno > 0) {
            g.setColor(255, 0, 0);
            g.fillRect(bw*1, yorig-h1, bw+1, h1);
        }
        if (frameno > 1) {
            g.setColor(0, 255, 0);
            g.fillRect(bw*3, yorig-h2, bw+1, h2);
        }
        if (frameno > 2) {
            g.setColor(0, 0, 255);
            g.fillRect(bw*5, yorig-h3, bw+1, h3);
        }

        g.setColor(0);
        g.drawRect(bw*1, yorig-h1, bw, h1);
        g.drawRect(bw*3, yorig-h2, bw, h2);
        g.drawRect(bw*5, yorig-h3, bw, h3);

        // Draw axis for bar chart.
        g.setGrayScale(0);
        g.drawLine(0, 0, 0, yorig);
        g.drawLine(0, yorig, barSize, yorig);
        g.setStrokeStyle(Graphics.DOTTED);
        g.drawLine(0, yorig - avg, barSize, yorig-avg);
        g.setStrokeStyle(Graphics.SOLID);

	// Restore to left and move down
        g.translate(-(w + pad) / 2, pieSize + pad);