ChartDirector 7.0 (ASP/COM/VB Edition)

Black Round Meters

          

This example demonstrates round meters with black background, silver border and glare effect.

The silver border effect is achieved by using AngularMeter.relativeLinearGradient to create a gradient consisting of varying levels of grey. The gradient is used as the fill color of the border ring created using AngularMeter.addRing. The ring is intentionally configured to be one pixel smaller than the black background circle. This leaves a thin black edge outside of the ring to help it stand out from the white external background.

Glare effect is added to some of the meters using AngularMeter.addGlare. Convex and concave glare at various angles are demonstrated. Glare effect works best in a dark background.

For some meters, a text box is added at the bottom using BaseChart.addText to display the meter value.

Source Code Listing

[Web Version (in ASP)] aspdemo\blackroundmeter.asp
<%@ language="vbscript" %> <% Set cd = CreateObject("ChartDirector.API") ' This script can draw different charts depending on the chartIndex Sub createChart(viewer, chartIndex) ' The value to display on the meter value = 72.3 ' Create an AngularMeter object of size 250 x 250 pixels with transparent background Set m = cd.AngularMeter(250, 250, cd.Transparent) ' Set the default text and line colors to white (0xffffff) Call m.setColor(cd.TextColor, &Hffffff) Call m.setColor(cd.LineColor, &Hffffff) ' Demonstration two different meter scale angles If chartIndex Mod 2 = 0 Then ' Center at (125, 125), scale radius = 111 pixels, scale angle -140 to +140 degrees Call m.setMeter(125, 125, 111, -140, 140) Else ' Center at (125, 125), scale radius = 111 pixels, scale angle -180 to +90 degrees Call m.setMeter(125, 125, 111, -180, 90) End If ' Add a black (0x000000) circle with radius 123 pixels as background Call m.addRing(0, 123, &H000000) ' Gradient color for the border to make it silver-like ringGradient = Array(1, &H7f7f7f, 0.5, &Hd6d6d6, 0, &Hffffff, -0.5, &Hd6d6d6, -1, &H7f7f7f) ' Add a ring between radii 116 and 122 pixels using the silver gradient as border Call m.addRing(116, 122, m.relativeLinearGradient(ringGradient, 45, 122)) ' Meter scale is 0 - 100, with major/minor/micro ticks every 10/5/1 units Call m.setScale(0, 100, 10, 5, 1) ' Set the scale label style to 15pt Arial Italic. Set the major/minor/micro tick lengths to ' 12/9/6 pixels pointing inwards, and their widths to 2/1/1 pixels. Call m.setLabelStyle("Arial Italic", 15) Call m.setTickLength(-12, -9, -6) Call m.setLineWidth(0, 2, 1, 1) ' Demostrate different types of color scales and glare effects and putting them at different ' positions. smoothColorScale = Array(0, &H0000ff, 25, &H0088ff, 50, &H00ff00, 75, &Hdddd00, 100, &Hff0000) stepColorScale = Array(0, &H00aa00, 60, &Hddaa00, 80, &Hcc0000, 100) highLowColorScale = Array(0, &H00ff00, 70, cd.Transparent, 100, &Hff0000) If chartIndex = 0 Then ' Add the smooth color scale at the default position Call m.addColorScale(smoothColorScale) ' Add glare up to radius 116 (= region inside border) Call m.addGlare(116) ElseIf chartIndex = 1 Then ' Add the smooth color scale starting at radius 62 with zero width and ending at radius 40 ' with 22 pixels outer width Call m.addColorScale(smoothColorScale, 62, 0, 40, 22) ' Add glare up to radius 116 (= region inside border), concave and spanning 190 degrees Call m.addGlare(116, -190) ElseIf chartIndex = 2 Then ' Add the smooth color scale starting at radius 111 with zero width and ending at radius 111 ' with 12 pixels inner width Call m.addColorScale(smoothColorScale, 111, 0, 111, -12) ' Add glare up to radius 116 (= region inside border), concave and spanning 190 degrees and ' rotated by 45 degrees Call m.addGlare(116, -190, 45) ElseIf chartIndex = 3 Then ' Add the high/low color scale at the default position Call m.addColorScale(highLowColorScale) ElseIf chartIndex = 4 Then ' Add the smooth color scale at radius 44 with 16 pixels outer width Call m.addColorScale(smoothColorScale, 44, 16) ' Add glare up to radius 116 (= region inside border), concave and spanning 190 degrees and ' rotated by -45 degrees Call m.addGlare(116, -190, -45) Else ' Add the step color scale at the default position Call m.addColorScale(stepColorScale) End If ' Add a text label centered at (125, 175) with 15pt Arial Italic font Call m.addText(125, 175, "CPU", "Arial Italic", 15, cd.TextColor, cd.Center) ' Add a readout to some of the charts as demonstration If (chartIndex = 0) Or (chartIndex = 2) Then ' Put the value label center aligned at (125, 232), using black (0x000000) 14pt Arial font ' on a light blue (0x99ccff) background. Set box width to 50 pixels with 5 pixels rounded ' corners. Set t = m.addText(125, 232, m.formatValue(value, _ "<*block,width=50,halign=center*>{value|1}"), "Arial", 14, &H000000, cd.BottomCenter) Call t.setBackground(&H99ccff) Call t.setRoundedCorners(5) End If ' Add a red (0xff0000) pointer at the specified value Call m.addPointer2(value, &Hff0000) ' Output the chart Call viewer.setChart(m, cd.SVG) End Sub ' This example includes 6 charts Dim viewers(5) For i = 0 To Ubound(viewers) Set viewers(i) = cd.WebChartViewer(Request, "chart" & i) Call createChart(viewers(i), i) Next %> <!DOCTYPE html> <html> <head> <title>Black Round Meters</title> <!-- Include ChartDirector Javascript Library to support chart interactions --> <script type="text/javascript" src="cdjcv.js"></script> </head> <body style="margin:5px 0px 0px 5px"> <div style="font:bold 18pt verdana;"> Black Round Meters </div> <hr style="border:solid 1px #000080; background:#000080" /> <div style="font:10pt verdana; margin-bottom:1.5em"> <a href="viewsource.asp?file=<%= Request("SCRIPT_NAME") %>">View Chart Source Code</a> </div> <!-- ****** Here are the chart images ****** --> <% For i = 0 To Ubound(viewers) Call Response.Write(viewers(i).renderHTML()) Call Response.Write(" ") Next %> </body> </html>

[Windows Version (in Visual Basic)] vbdemo\blackroundmeter.cls
Public Sub createChart(viewer As Object, chartIndex As Integer) Dim cd As New ChartDirector.API ' The value to display on the meter Dim value As Double value = 72.3 ' Create an AngularMeter object of size 250 x 250 pixels Dim m As AngularMeter Set m = cd.AngularMeter(250, 250) ' Set the default text and line colors to white (0xffffff) Call m.setColor(cd.TextColor, &Hffffff) Call m.setColor(cd.LineColor, &Hffffff) ' Demonstration two different meter scale angles If chartIndex Mod 2 = 0 Then ' Center at (125, 125), scale radius = 111 pixels, scale angle -140 to +140 degrees Call m.setMeter(125, 125, 111, -140, 140) Else ' Center at (125, 125), scale radius = 111 pixels, scale angle -180 to +90 degrees Call m.setMeter(125, 125, 111, -180, 90) End If ' Add a black (0x000000) circle with radius 123 pixels as background Call m.addRing(0, 123, &H000000) ' Gradient color for the border to make it silver-like Dim ringGradient() ringGradient = Array(1, &H7f7f7f, 0.5, &Hd6d6d6, 0, &Hffffff, -0.5, &Hd6d6d6, -1, &H7f7f7f) ' Add a ring between radii 116 and 122 pixels using the silver gradient as border Call m.addRing(116, 122, m.relativeLinearGradient(ringGradient, 45, 122)) ' Meter scale is 0 - 100, with major/minor/micro ticks every 10/5/1 units Call m.setScale(0, 100, 10, 5, 1) ' Set the scale label style to 15pt Arial Italic. Set the major/minor/micro tick lengths to ' 12/9/6 pixels pointing inwards, and their widths to 2/1/1 pixels. Call m.setLabelStyle("ariali.ttf", 15) Call m.setTickLength(-12, -9, -6) Call m.setLineWidth(0, 2, 1, 1) ' Demostrate different types of color scales and glare effects and putting them at different ' positions. Dim smoothColorScale() smoothColorScale = Array(0, &H0000ff, 25, &H0088ff, 50, &H00ff00, 75, &Hdddd00, 100, &Hff0000) Dim stepColorScale() stepColorScale = Array(0, &H00aa00, 60, &Hddaa00, 80, &Hcc0000, 100) Dim highLowColorScale() highLowColorScale = Array(0, &H00ff00, 70, cd.Transparent, 100, &Hff0000) If chartIndex = 0 Then ' Add the smooth color scale at the default position Call m.addColorScale(smoothColorScale) ' Add glare up to radius 116 (= region inside border) Call m.addGlare(116) ElseIf chartIndex = 1 Then ' Add the smooth color scale starting at radius 62 with zero width and ending at radius 40 ' with 22 pixels outer width Call m.addColorScale(smoothColorScale, 62, 0, 40, 22) ' Add glare up to radius 116 (= region inside border), concave and spanning 190 degrees Call m.addGlare(116, -190) ElseIf chartIndex = 2 Then ' Add the smooth color scale starting at radius 111 with zero width and ending at radius 111 ' with 12 pixels inner width Call m.addColorScale(smoothColorScale, 111, 0, 111, -12) ' Add glare up to radius 116 (= region inside border), concave and spanning 190 degrees and ' rotated by 45 degrees Call m.addGlare(116, -190, 45) ElseIf chartIndex = 3 Then ' Add the high/low color scale at the default position Call m.addColorScale(highLowColorScale) ElseIf chartIndex = 4 Then ' Add the smooth color scale at radius 44 with 16 pixels outer width Call m.addColorScale(smoothColorScale, 44, 16) ' Add glare up to radius 116 (= region inside border), concave and spanning 190 degrees and ' rotated by -45 degrees Call m.addGlare(116, -190, -45) Else ' Add the step color scale at the default position Call m.addColorScale(stepColorScale) End If ' Add a text label centered at (125, 175) with 15pt Arial Italic font Call m.addText(125, 175, "CPU", "ariali.ttf", 15, cd.TextColor, cd.Center) ' Add a readout to some of the charts as demonstration If chartIndex = 0 Or chartIndex = 2 Then ' Put the value label center aligned at (125, 232), using black (0x000000) 14pt Arial font ' on a light blue (0x99ccff) background. Set box width to 50 pixels with 5 pixels rounded ' corners. Dim t As ChartDirector.TextBox Set t = m.addText(125, 232, m.formatValue(value, _ "<*block,width=50,halign=center*>{value|1}"), "arial.ttf", 14, &H000000, _ cd.BottomCenter) Call t.setBackground(&H99ccff) Call t.setRoundedCorners(5) End If ' Add a red (0xff0000) pointer at the specified value Call m.addPointer2(value, &Hff0000) ' Output the chart Set viewer.Picture = m.makePicture() End Sub

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