Circular Bar Meter (2)

pythondemo\circularbarmeter2.py
#!/usr/bin/python

# The ChartDirector for Python module is assumed to be in "../lib"
import sys, os
sys.path.insert(0, os.path.join(os.path.abspath(sys.path[0]), "..", "lib"))

from pychartdir import *

def createChart(chartIndex) :

    # The value to display on the meter
    value = 85

    # The meter radius and angle
    radius = 50
    angle = value * 360.0 / 100

    # Create an AngularMeter with transparent background
    m = AngularMeter(radius * 2 + 10, radius * 2 + 10, Transparent)

    # Set the center, radius and angular range of the meter
    m.setMeter(int(m.getWidth() / 2), int(m.getHeight() / 2), radius, 0, 360)

    # For circular bar meters, we do not need pointer or graduation, so we hide them.
    m.setMeterColors(Transparent, Transparent, Transparent)
    m.setCap(0, Transparent)

    # In this example, the circular bar has 20 segments
    segmentCount = 20

    # The angular step
    angleStep = 360.0 / segmentCount

    # The gap between segments is 4.5 degrees
    angleGap = 4.5

    #
    # This example demonstrates several coloring styles
    #

    # Thd default fill and blank colors
    fillColor = 0x336699
    blankColor = 0xeeeeee

    if chartIndex >= 4 :
        # Use dark background style
        m.setColors(whiteOnBlackPalette)
        fillColor = 0x6699ff
        blankColor = 0x222222

    if chartIndex % 4 == 1 :
        # Alternative fill color
        fillColor = 0x00ee33
    elif chartIndex % 4 == 2 :
        # Use a smooth color scale as the fill color
        smoothColorScale = [0, 0x0022ff, 15, 0x0088ff, 30, 0x00ff00, 55, 0xffff00, 80, 0xff0000,
            100, 0xff0000]
        fillColor = m.getDrawArea().angleGradientColor(int(m.getWidth() / 2), int(m.getHeight() / 2
            ), 0, 360, radius, radius - 20, smoothColorScale)
    elif chartIndex % 4 == 3 :
        # Use a step color scale as the fill color
        stepColorScale = [0, 0x0044ff, 20, 0x00ee00, 50, 0xeeee00, 70, 0xee0000, 100]
        fillColor = m.getDrawArea().angleGradientColor(int(m.getWidth() / 2), int(m.getHeight() / 2
            ),  - angleGap / 2, 360 - angleGap / 2, radius, radius - 20, stepColorScale)

    #
    # Now we draw the segments of the bar meter
    #

    # The segment that contains the value
    currentSegment = int(angle / angleStep)

    # Segments after the current segment is colored with the blank color
    for i in range(currentSegment + 1, segmentCount) :
        m.addRingSector(radius, radius - 20, i * angleStep, (i + 1) * angleStep - angleGap,
            blankColor)

    # Segments before the current segment is colored with the fill color
    for i in range(0, currentSegment) :
        m.addRingSector(radius, radius - 20, i * angleStep, (i + 1) * angleStep - angleGap,
            fillColor)

    # Segment that contains the angle will be partially filled and partially blank. We need to
    # adjust the angle to compensated for the angle gap.
    adjustedAngle = currentSegment * angleStep + (angle - currentSegment * angleStep) * (
        1 - angleGap / angleStep)

    # The blank part of the segment
    if (currentSegment + 1) * angleStep > angle :
        m.addRingSector(radius, radius - 20, adjustedAngle, (currentSegment + 1
            ) * angleStep - angleGap, blankColor)

    # The filled part of the segment.
    if angle > currentSegment * angleStep :
        m.addRingSector(radius, radius - 20, currentSegment * angleStep, adjustedAngle, fillColor)

    # Add a label at the center to display the value
    m.addText(int(m.getWidth() / 2), int(m.getHeight() / 2), m.formatValue(value, "{value}"),
        "Arial", 25, TextColor, Center).setMargin(0)

    # Output the chart
    m.makeChart("circularbarmeter2%s.png" % chartIndex)


createChart(0)
createChart(1)
createChart(2)
createChart(3)
createChart(4)
createChart(5)
createChart(6)
createChart(7)