commitlist.go

package main

import (
	"image"
	"image/color"

	"gioui.org/font"
	"gioui.org/layout"
	"gioui.org/op"
	"gioui.org/op/clip"
	"gioui.org/op/paint"
	"gioui.org/unit"
	"gioui.org/widget"
	"gioui.org/widget/material"
)

// CommitList displays a searchable list of commits.
type CommitList struct {
	All      []Commit
	Filtered []Commit

	Search widget.Editor
	List   SelectList

	lastQuery string
}

// NewCommitList creates a new CommitList.
func NewCommitList(th *Theme) CommitList {
	cl := CommitList{}
	cl.Search.SingleLine = true
	cl.List = NewVerticalSelectList(unit.Dp(th.TextSize) + 6)
	return cl
}

// SetCommits updates the full commit list.
func (cl *CommitList) SetCommits(commits []Commit) {
	cl.All = commits
	cl.Filtered = commits
	if len(commits) > 0 && cl.List.Selected < 0 {
		cl.List.Selected = 0
	}
}

// Selected returns the currently selected commit, or nil.
func (cl *CommitList) Selected() *Commit {
	if cl.List.Selected >= 0 && cl.List.Selected < len(cl.Filtered) {
		return &cl.Filtered[cl.List.Selected]
	}
	return nil
}

// Layout draws the commit list with search.
func (cl *CommitList) Layout(th *Theme, gtx layout.Context) (selectionChanged bool) {
	prevSelected := cl.List.Selected

	// Process search editor events.
	changed := false
	for {
		ev, ok := cl.Search.Update(gtx)
		if !ok {
			break
		}
		if _, ok := ev.(widget.ChangeEvent); ok {
			changed = true
		}
	}

	if changed {
		cl.lastQuery = cl.Search.Text()
		gtx.Execute(op.InvalidateCmd{})
	}

	layout.Flex{
		Axis: layout.Vertical,
	}.Layout(gtx,
		layout.Rigid(func(gtx layout.Context) layout.Dimensions {
			return FocusBorder(th, gtx.Focused(&cl.Search)).Layout(gtx,
				material.Editor(th.Theme, &cl.Search, "Search commits...").Layout)
		}),
		layout.Flexed(1, func(gtx layout.Context) layout.Dimensions {
			return cl.List.Layout(th, gtx, len(cl.Filtered), cl.commitItem(th))
		}),
	)

	return cl.List.Selected != prevSelected
}

// UpdateFilter should be called when search results are available.
func (cl *CommitList) UpdateFilter(results []Commit) {
	cl.Filtered = results
	if cl.List.Selected >= len(cl.Filtered) {
		cl.List.Selected = len(cl.Filtered) - 1
	}
	if cl.List.Selected < 0 && len(cl.Filtered) > 0 {
		cl.List.Selected = 0
	}
}

// Query returns the current search query.
func (cl *CommitList) Query() string {
	return cl.lastQuery
}

func commitLabel(th *Theme, style ListItemStyle, text string) material.LabelStyle {
	label := material.Body1(th.Theme, text)
	label.Color = style.Foreground
	label.MaxLines = 1
	label.TextSize = th.TextSize * 8 / 10
	return label
}

func (cl *CommitList) commitItem(th *Theme) layout.ListElement {
	return func(gtx layout.Context, index int) layout.Dimensions {
		commit := &cl.Filtered[index]
		height := gtx.Constraints.Min.Y
		dims := cl.List.LayoutItem(th, gtx, index, func(gtx layout.Context, style ListItemStyle) layout.Dimensions {
			return layout.Flex{
				Axis:      layout.Horizontal,
				Alignment: layout.Baseline,
			}.Layout(gtx,
				// Short hash.
				layout.Rigid(func(gtx layout.Context) layout.Dimensions {
					return FixedWidth(gtx, gtx.Metric.Sp(th.TextSize*6), func(gtx layout.Context) layout.Dimensions {
						label := commitLabel(th, style, commit.ShortHash())
						label.Font = font.Font{Typeface: th.Face}
						return label.Layout(gtx)
					})
				}),
				// Subject (fills remaining space, pushing right-aligned items).
				layout.Flexed(1, func(gtx layout.Context) layout.Dimensions {
					label := commitLabel(th, style, commit.Subject)
					label.Font.Weight = style.Weight
					return label.Layout(gtx)
				}),
				// Decorations.
				layout.Rigid(func(gtx layout.Context) layout.Dimensions {
					if len(commit.Decorations) == 0 {
						return layout.Dimensions{}
					}
					return layout.Inset{Left: 4}.Layout(gtx, func(gtx layout.Context) layout.Dimensions {
						return layoutDecorations(th, gtx, commit.Decorations)
					})
				}),
				// Author (right-aligned).
				layout.Rigid(func(gtx layout.Context) layout.Dimensions {
					return layout.Inset{Left: 8}.Layout(gtx, func(gtx layout.Context) layout.Dimensions {
						return FixedWidth(gtx, gtx.Metric.Sp(th.TextSize*10), func(gtx layout.Context) layout.Dimensions {
							return commitLabel(th, style, commit.AuthorName).Layout(gtx)
						})
					})
				}),
				// Date (right-aligned).
				layout.Rigid(func(gtx layout.Context) layout.Dimensions {
					return layout.Inset{Left: 4}.Layout(gtx, func(gtx layout.Context) layout.Dimensions {
						return FixedWidth(gtx, gtx.Metric.Sp(th.TextSize*10), func(gtx layout.Context) layout.Dimensions {
							return commitLabel(th, style, commit.RelativeDate()).Layout(gtx)
						})
					})
				}),
			)
		})
		dims.Size.Y = height
		return dims
	}
}

func layoutDecorations(th *Theme, gtx layout.Context, decs []Decoration) layout.Dimensions {
	var children []layout.FlexChild
	for i := range decs {
		dec := &decs[i]
		children = append(children,
			layout.Rigid(func(gtx layout.Context) layout.Dimensions {
				return layout.Inset{Left: 2, Top: 1, Bottom: 1}.Layout(gtx, func(gtx layout.Context) layout.Dimensions {
					return layoutBadge(th, gtx, dec)
				})
			}),
		)
	}
	return layout.Flex{
		Axis:      layout.Horizontal,
		Alignment: layout.Baseline,
	}.Layout(gtx, children...)
}

func layoutBadge(th *Theme, gtx layout.Context, dec *Decoration) layout.Dimensions {
	var fg, bg color.NRGBA
	switch dec.Kind {
	case DecorationBranch:
		fg, bg = th.Colors.BranchColor, th.Colors.BranchBg
	case DecorationTag:
		fg, bg = th.Colors.TagColor, th.Colors.TagBg
	case DecorationHead:
		fg, bg = th.Colors.HeadColor, th.Colors.HeadBg
	}

	return layout.Background{}.Layout(gtx,
		func(gtx layout.Context) layout.Dimensions {
			bounds := clip.UniformRRect(image.Rectangle{Max: gtx.Constraints.Min}, gtx.Metric.Dp(3))
			paint.FillShape(gtx.Ops, bg, bounds.Op(gtx.Ops))
			return layout.Dimensions{Size: gtx.Constraints.Min}
		},
		func(gtx layout.Context) layout.Dimensions {
			inset := layout.Inset{Top: 1, Bottom: 1, Left: 3, Right: 3}
			return inset.Layout(gtx, func(gtx layout.Context) layout.Dimensions {
				gtx.Constraints.Min.Y = 0
				label := material.Body1(th.Theme, dec.Name)
				label.Color = fg
				label.MaxLines = 1
				label.TextSize = th.TextSize * 7 / 10
				return label.Layout(gtx)
			})
		},
	)
}