better default handling around final value labels.
This commit is contained in:
parent
b10ead7cc1
commit
5c8836f9bd
4 changed files with 115 additions and 80 deletions
3
box.go
3
box.go
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@ -8,6 +8,9 @@ type Box struct {
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Left int
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Right int
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Bottom int
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Height int
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Width int
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}
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// IsZero returns if the box is set or not.
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159
chart.go
159
chart.go
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@ -27,40 +27,6 @@ type Chart struct {
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Series []Series
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}
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// GetCanvasTop gets the top corner pixel.
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func (c Chart) GetCanvasTop() int {
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return c.Background.Padding.GetTop(DefaultBackgroundPadding.Top)
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}
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// GetCanvasLeft gets the left corner pixel.
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func (c Chart) GetCanvasLeft() int {
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return c.Background.Padding.GetLeft(DefaultBackgroundPadding.Left)
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}
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// GetCanvasBottom gets the bottom corner pixel.
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func (c Chart) GetCanvasBottom() int {
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return c.Height - c.Background.Padding.GetBottom(DefaultBackgroundPadding.Bottom)
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}
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// GetCanvasRight gets the right corner pixel.
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func (c Chart) GetCanvasRight() int {
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return c.Width - c.Background.Padding.GetRight(DefaultBackgroundPadding.Right)
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}
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// GetCanvasWidth returns the width of the canvas.
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func (c Chart) GetCanvasWidth() int {
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pl := c.Background.Padding.GetLeft(DefaultBackgroundPadding.Left)
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pr := c.Background.Padding.GetRight(DefaultBackgroundPadding.Right)
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return c.Width - (pl + pr)
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}
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// GetCanvasHeight returns the height of the canvas.
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func (c Chart) GetCanvasHeight() int {
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pt := c.Background.Padding.GetTop(DefaultBackgroundPadding.Top)
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pb := c.Background.Padding.GetBottom(DefaultBackgroundPadding.Bottom)
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return c.Height - (pt + pb)
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}
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// GetFont returns the text font.
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func (c Chart) GetFont() (*truetype.Font, error) {
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if c.Font != nil {
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@ -71,26 +37,78 @@ func (c Chart) GetFont() (*truetype.Font, error) {
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// Render renders the chart with the given renderer to the given io.Writer.
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func (c *Chart) Render(provider RendererProvider, w io.Writer) error {
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xrange, yrange := c.initRanges()
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font, err := c.GetFont()
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if err != nil {
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return err
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r := provider(c.Width, c.Height)
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if c.hasText() {
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font, err := c.GetFont()
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if err != nil {
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return err
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}
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r.SetFont(font)
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}
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r := provider(c.Width, c.Height)
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r.SetFont(font)
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canvasBox := c.calculateCanvasBox(r)
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xrange, yrange := c.initRanges(canvasBox)
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c.drawBackground(r)
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c.drawCanvas(r)
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c.drawAxes(r, xrange, yrange)
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c.drawCanvas(r, canvasBox)
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c.drawAxes(r, canvasBox, xrange, yrange)
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for index, series := range c.Series {
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c.drawSeries(r, index, series, xrange, yrange)
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c.drawSeries(r, canvasBox, index, series, xrange, yrange)
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}
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c.drawTitle(r)
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return r.Save(w)
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}
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func (c Chart) initRanges() (xrange Range, yrange Range) {
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func (c Chart) hasText() bool {
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return c.TitleStyle.Show || c.Axes.Show
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}
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func (c Chart) calculateCanvasBox(r Renderer) Box {
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dpr := DefaultBackgroundPadding.Right
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finalLabelWidth := c.calculateFinalLabelWidth(r)
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if finalLabelWidth > dpr {
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dpr = finalLabelWidth
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}
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dpb := DefaultBackgroundPadding.Bottom
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cb := Box{
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Top: c.Background.Padding.GetTop(DefaultBackgroundPadding.Top),
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Left: c.Background.Padding.GetLeft(DefaultBackgroundPadding.Left),
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Right: c.Width - c.Background.Padding.GetRight(dpr),
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Bottom: c.Height - c.Background.Padding.GetBottom(dpb),
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}
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cb.Height = cb.Bottom - cb.Top
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cb.Width = cb.Right - cb.Left
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return cb
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}
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func (c Chart) calculateFinalLabelWidth(r Renderer) int {
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if !c.FinalValueLabel.Show {
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return 0
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}
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var finalLabelText string
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for _, s := range c.Series {
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_, ll := s.GetLabel(s.Len() - 1)
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if len(finalLabelText) < len(ll) {
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finalLabelText = ll
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}
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}
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r.SetFontSize(c.FinalValueLabel.GetFontSize(DefaultFinalLabelFontSize))
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textWidth := r.MeasureText(finalLabelText)
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pl := c.FinalValueLabel.Padding.GetLeft(DefaultFinalLabelPadding.Left)
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pr := c.FinalValueLabel.Padding.GetRight(DefaultFinalLabelPadding.Right)
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asw := int(c.Axes.GetStrokeWidth(DefaultAxisLineWidth))
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lsw := int(c.FinalValueLabel.GetStrokeWidth(DefaultAxisLineWidth))
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return DefaultFinalLabelDeltaWidth +
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pl + pr +
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textWidth + asw + 2*lsw
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}
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func (c Chart) initRanges(canvasBox Box) (xrange Range, yrange Range) {
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//iterate over each series, pull out the min/max for x,y
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var didSetFirstValues bool
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var globalMinY, globalMinX float64
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@ -127,7 +145,7 @@ func (c Chart) initRanges() (xrange Range, yrange Range) {
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xrange.Min = c.XRange.Min
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xrange.Max = c.XRange.Max
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}
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xrange.Domain = c.GetCanvasWidth()
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xrange.Domain = canvasBox.Width
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if c.YRange.IsZero() {
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yrange.Min = globalMinY
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@ -136,40 +154,44 @@ func (c Chart) initRanges() (xrange Range, yrange Range) {
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yrange.Min = c.YRange.Min
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yrange.Max = c.YRange.Max
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}
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yrange.Domain = c.GetCanvasHeight()
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yrange.Domain = canvasBox.Height
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return
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}
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func (c Chart) drawBackground(r Renderer) {
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r.SetFillColor(c.Background.GetFillColor(DefaultBackgroundColor))
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r.SetStrokeColor(c.Background.GetStrokeColor(DefaultBackgroundStrokeColor))
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r.SetLineWidth(c.Background.GetStrokeWidth(DefaultStrokeWidth))
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r.MoveTo(0, 0)
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r.LineTo(c.Width, 0)
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r.LineTo(c.Width, c.Height)
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r.LineTo(0, c.Height)
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r.LineTo(0, 0)
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r.Close()
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r.Fill()
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r.FillStroke()
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}
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func (c Chart) drawCanvas(r Renderer) {
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func (c Chart) drawCanvas(r Renderer, canvasBox Box) {
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r.SetFillColor(c.Canvas.GetFillColor(DefaultCanvasColor))
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r.MoveTo(c.GetCanvasLeft(), c.GetCanvasTop())
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r.LineTo(c.GetCanvasRight(), c.GetCanvasTop())
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r.LineTo(c.GetCanvasRight(), c.GetCanvasBottom())
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r.LineTo(c.GetCanvasLeft(), c.GetCanvasBottom())
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r.LineTo(c.GetCanvasLeft(), c.GetCanvasTop())
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r.Fill()
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r.SetStrokeColor(c.Canvas.GetStrokeColor(DefaultCanvasStrokColor))
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r.SetLineWidth(c.Canvas.GetStrokeWidth(DefaultStrokeWidth))
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r.MoveTo(canvasBox.Left, canvasBox.Top)
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r.LineTo(canvasBox.Right, canvasBox.Top)
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r.LineTo(canvasBox.Right, canvasBox.Bottom)
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r.LineTo(canvasBox.Left, canvasBox.Bottom)
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r.LineTo(canvasBox.Left, canvasBox.Top)
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r.Close()
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r.FillStroke()
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}
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func (c Chart) drawAxes(r Renderer, xrange, yrange Range) {
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func (c Chart) drawAxes(r Renderer, canvasBox Box, xrange, yrange Range) {
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if c.Axes.Show {
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r.SetStrokeColor(c.Axes.GetStrokeColor(DefaultAxisColor))
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r.SetLineWidth(c.Axes.GetStrokeWidth(DefaultStrokeWidth))
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r.MoveTo(c.GetCanvasLeft(), c.GetCanvasBottom())
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r.LineTo(c.GetCanvasRight(), c.GetCanvasBottom())
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r.LineTo(c.GetCanvasRight(), c.GetCanvasTop())
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r.MoveTo(canvasBox.Left, canvasBox.Bottom)
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r.LineTo(canvasBox.Right, canvasBox.Bottom)
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r.LineTo(canvasBox.Right, canvasBox.Top)
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r.Stroke()
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c.drawAxesLabels(r, xrange, yrange)
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@ -181,7 +203,7 @@ func (c Chart) drawAxesLabels(r Renderer, xrange, yrange Range) {
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// do y axis
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}
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func (c Chart) drawSeries(r Renderer, index int, s Series, xrange, yrange Range) {
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func (c Chart) drawSeries(r Renderer, canvasBox Box, index int, s Series, xrange, yrange Range) {
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r.SetStrokeColor(s.GetStyle().GetStrokeColor(GetDefaultSeriesStrokeColor(index)))
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r.SetLineWidth(s.GetStyle().GetStrokeWidth(DefaultStrokeWidth))
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@ -189,9 +211,9 @@ func (c Chart) drawSeries(r Renderer, index int, s Series, xrange, yrange Range)
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return
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}
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cx := c.GetCanvasLeft()
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cy := c.GetCanvasTop()
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cw := c.GetCanvasWidth()
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cx := canvasBox.Left
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cy := canvasBox.Top
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cw := canvasBox.Width
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v0x, v0y := s.GetValue(0)
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x0 := cw - xrange.Translate(v0x)
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@ -208,24 +230,23 @@ func (c Chart) drawSeries(r Renderer, index int, s Series, xrange, yrange Range)
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}
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r.Stroke()
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c.drawFinalValueLabel(r, index, s, yrange)
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c.drawFinalValueLabel(r, canvasBox, index, s, yrange)
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}
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func (c Chart) drawFinalValueLabel(r Renderer, index int, s Series, yrange Range) {
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func (c Chart) drawFinalValueLabel(r Renderer, canvasBox Box, index int, s Series, yrange Range) {
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if c.FinalValueLabel.Show {
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_, lv := s.GetValue(s.Len() - 1)
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_, ll := s.GetLabel(s.Len() - 1)
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py := c.GetCanvasTop()
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py := canvasBox.Top
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ly := yrange.Translate(lv) + py
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r.SetFontSize(c.FinalValueLabel.GetFontSize(DefaultFinalLabelFontSize))
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textWidth := r.MeasureText(ll)
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textHeight := int(math.Floor(DefaultFinalLabelFontSize))
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halfTextHeight := textHeight >> 1
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cx := c.GetCanvasRight() + int(c.Axes.GetStrokeWidth(DefaultAxisLineWidth))
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cx := canvasBox.Right + int(c.Axes.GetStrokeWidth(DefaultAxisLineWidth))
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pt := c.FinalValueLabel.Padding.GetTop(DefaultFinalLabelPadding.Top)
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pl := c.FinalValueLabel.Padding.GetLeft(DefaultFinalLabelPadding.Left)
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@ -272,7 +293,7 @@ func (c Chart) drawTitle(r Renderer) error {
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r.SetFontSize(titleFontSize)
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textWidth := r.MeasureText(c.Title)
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titleX := (c.Width >> 1) - (textWidth >> 1)
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titleY := c.GetCanvasTop() + int(titleFontSize)
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titleY := c.TitleStyle.Padding.GetTop(DefaultTitleTop) + int(titleFontSize)
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r.Text(c.Title, titleX, titleY)
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}
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return nil
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10
defaults.go
10
defaults.go
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@ -28,6 +28,8 @@ const (
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DefaultFinalLabelDeltaWidth = 10
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// DefaultFinalLabelFontSize is the font size of the final label.
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DefaultFinalLabelFontSize = 10.0
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// DefaultTitleTop is the default distance from the top of the chart to put the title.
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DefaultTitleTop = 10
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// DefaultDateFormat is the default date format.
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DefaultDateFormat = "2006-01-02"
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)
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@ -36,9 +38,15 @@ var (
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// DefaultBackgroundColor is the default chart background color.
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// It is equivalent to css color:white.
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DefaultBackgroundColor = color.RGBA{R: 255, G: 255, B: 255, A: 255}
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// DefaultBackgroundStrokeColor is the default chart border color.
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// It is equivalent to color:white.
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DefaultBackgroundStrokeColor = color.RGBA{R: 255, G: 255, B: 255, A: 255}
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// DefaultCanvasColor is the default chart canvas color.
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// It is equivalent to css color:white.
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DefaultCanvasColor = color.RGBA{R: 255, G: 255, B: 255, A: 255}
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// DefaultCanvasStrokColor is the default chart canvas stroke color.
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// It is equivalent to css color:white.
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DefaultCanvasStrokColor = color.RGBA{R: 255, G: 255, B: 255, A: 255}
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// DefaultTextColor is the default chart text color.
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// It is equivalent to #333333.
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DefaultTextColor = color.RGBA{R: 51, G: 51, B: 51, A: 255}
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@ -75,7 +83,7 @@ var (
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// DefaultFinalLabelPadding is the padding around the final label.
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DefaultFinalLabelPadding = Box{Top: 5, Left: 0, Right: 5, Bottom: 5}
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// DefaultBackgroundPadding is the default canvas padding config.
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DefaultBackgroundPadding = Box{Top: 5, Left: 5, Right: 40, Bottom: 40}
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DefaultBackgroundPadding = Box{Top: 5, Left: 5, Right: 5, Bottom: 5}
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)
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var (
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@ -17,31 +17,34 @@ func main() {
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rc.Response.Header().Set("Content-Type", "image/png")
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now := time.Now()
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c := chart.Chart{
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Title: "Stocks Bruh.",
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Title: "A Test Chart",
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TitleStyle: chart.Style{
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Show: true,
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},
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Width: 1024,
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Height: 400,
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Canvas: chart.Style{
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Padding: chart.Box{
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Right: 40,
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Bottom: 40,
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},
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},
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Width: 800,
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Height: 380,
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Axes: chart.Style{
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Show: true,
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StrokeWidth: 1.0,
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},
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YRange: chart.Range{
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Min: 0.0,
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Max: 7.0,
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},
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FinalValueLabel: chart.Style{
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Show: true,
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},
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Series: []chart.Series{
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chart.TimeSeries{
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Name: "goog",
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Name: "a",
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XValues: []time.Time{now.AddDate(0, 0, -4), now.AddDate(0, 0, -3), now.AddDate(0, 0, -2), now.AddDate(0, 0, -1)},
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YValues: []float64{2.5, 5.0, 2.0, 3.0},
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},
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chart.TimeSeries{
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Name: "b",
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XValues: []time.Time{now.AddDate(0, 0, -4), now.AddDate(0, 0, -3), now.AddDate(0, 0, -2), now.AddDate(0, 0, -1)},
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YValues: []float64{6.0, 5.0, 4.0, 1.0},
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},
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},
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}
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