Charting Components
From OpenLaszlo
Contents |
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High-level Goals/Requirements
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Chart types
Support for standard 2D, rectilinear, cartesian charts
- scatterplot
- line charts
- bar charts
- area charts
- bubble charts
We will also provide some support for
- Pie charts
Can you also support?
- Stacked Bar Charts
- Groupable Stacked Bar Charts.
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Data
- Data access via LZX datasets
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Series data
- Types of series
- linear (integer, float)
- categorical series (string)
- tip text
- Support for multiple dataseries
- enable/disable (bell&whistle: fade in/out)
- Text label
- Tip ?
- callback/method to compute a series column (incloding tips)
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Chart features
- conversion between chart view coordinates and data/axes values
- chart title (extensible rendering)
- default width, height?
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plot area
- chart specific rendering
- hit detection for data values
- background resource
- opacity
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axes (for 2d charts)
- extensible rendering
- tic marks
- enable/disable
- apis for either # of tics or spacing between tics
- major tics (extensible rendering)
- minor tics (extensible rendering)
- tic mark labels
- enable/disable
- axis label
- enable/disable
- auto min/max/zero-ing
- extenisble rendering of axis
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Legend
- title (extensible rendering)
- default internal layout (vertical)
- positioning (left, right, top, bottom) - EDB: this can be implemented easily outside the api via a containing view and a relatively simple layout, or even just some contraints.
- marker and series label layout (marker on left)
- auto size to content
- text style properties on title and series labels
- Extensible rendering of all chart features
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Text styles
- font properties
- rotation (only works with embedded fonts)
- extends/uses exising <style> componentry
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Line stroke and fill styles
- line stroke
- width
- linestyle (future release)
- color
- opacity
- fill
- gradient properties
- bgcolor
- fgcolor
- opacity
- image
- tile/stretch/crop
- extends/uses existing <style> componentry as makes sense
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Chart adornments
- value lines
- value regions
- value points
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Interactivity
- display of tips for individual data items
- zoom/pan/scroll for 2D chart plot areas
- hit detection for individual char elements and legend
- Drill down to other charts by clicking on chart reigons. Example clicking on a sector of a pie chart can open another pie chart, showing the details of that sector only.
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Additional Goals
- Reasonable interoperability with grid components
- Performance goals
- Max 1000 lines or points per chart.
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