Fix panic when tabs.popHistory is nonexistent - aerc - mirror of ~rjarry's aerc fork

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author	Drew DeVault <sir@cmpwn.com>	2019-07-25 08:29:10 -0400
committer	Drew DeVault <sir@cmpwn.com>	2019-07-25 08:29:10 -0400
commit	2f626ddd18e8472e0ddc2bb9013b7d01c1b5b9a9 (patch)
tree	fb39de5981ea9c4923d12c1bb176e52af5520183 /commands/account/select.go
parent	fe2fef4b750e570361eabc849c1ec09fe5eda01d (diff)
download	aerc-2f626ddd18e8472e0ddc2bb9013b7d01c1b5b9a9.tar.gz

Fix panic when tabs.popHistory is nonexistent

Diffstat (limited to 'commands/account/select.go')

0 files changed, 0 insertions, 0 deletions

package ui import ( "fmt" "math" "sync" "sync/atomic" ) type Grid struct { Invalidatable rows []GridSpec rowLayout []gridLayout columns []GridSpec columnLayout []gridLayout invalid bool // Protected by mutex cells []*GridCell mutex sync.RWMutex } const ( SIZE_EXACT = iota SIZE_WEIGHT = iota ) // Specifies the layout of a single row or column type GridSpec struct { // One of SIZE_EXACT or SIZE_WEIGHT Strategy int // If Strategy = SIZE_EXACT, this is the number of cells this row/col shall // occupy. If SIZE_WEIGHT, the space left after all exact rows/cols are // measured is distributed amonst the remainder weighted by this value. Size int } // Used to cache layout of each row/column type gridLayout struct { Offset int Size int } type GridCell struct { Row int Column int RowSpan int ColSpan int Content Drawable invalid atomic.Value // bool } func NewGrid() *Grid { return &Grid{invalid: true} } func (cell *GridCell) At(row, col int) *GridCell { cell.Row = row cell.Column = col return cell } func (cell *GridCell) Span(rows, cols int) *GridCell { cell.RowSpan = rows cell.ColSpan = cols return cell } func (grid *Grid) Rows(spec []GridSpec) *Grid { grid.rows = spec return grid } func (grid *Grid) Columns(spec []GridSpec) *Grid { grid.columns = spec return grid } func (grid *Grid) Children() []Drawable { grid.mutex.RLock() defer grid.mutex.RUnlock() children := make([]Drawable, len(grid.cells)) for i, cell := range grid.cells { children[i] = cell.Content } return children } func (grid *Grid) Draw(ctx *Context) { invalid := grid.invalid if invalid { grid.reflow(ctx) } grid.mutex.RLock() defer grid.mutex.RUnlock() for _, cell := range grid.cells { cellInvalid := cell.invalid.Load().(bool) if !cellInvalid && !invalid { continue } rows := grid.rowLayout[cell.Row : cell.Row+cell.RowSpan] cols := grid.columnLayout[cell.Column : cell.Column+cell.ColSpan] x := cols[0].Offset y := rows[0].Offset width := 0 height := 0 for _, col := range cols { width += col.Size } for _, row := range rows { height += row.Size } subctx := ctx.Subcontext(x, y, width, height) cell.Content.Draw(subctx) } } func (grid *Grid) reflow(ctx *Context) { grid.rowLayout = nil grid.columnLayout = nil flow := func(specs *[]GridSpec, layouts *[]gridLayout, extent int) { exact := 0 weight := 0 nweights := 0 for _, spec := range *specs { if spec.Strategy == SIZE_EXACT { exact += spec.Size } else if spec.Strategy == SIZE_WEIGHT { nweights += 1 weight += spec.Size } } offset := 0 for _, spec := range *specs { layout := gridLayout{Offset: offset} if spec.Strategy == SIZE_EXACT { layout.Size = spec.Size } else if spec.Strategy == SIZE_WEIGHT { size := float64(spec.Size) / float64(weight) size *= float64(extent - exact) layout.Size = int(math.Floor(size)) } offset += layout.Size *layouts = append(*layouts, layout) } } flow(&grid.rows, &grid.rowLayout, ctx.Height()) flow(&grid.columns, &grid.columnLayout, ctx.Width()) grid.invalid = false } func (grid *Grid) invalidateLayout() { grid.invalid = true grid.DoInvalidate(grid) } func (grid *Grid) Invalidate() { grid.invalidateLayout() grid.mutex.RLock() for _, cell := range grid.cells { cell.Content.Invalidate() } grid.mutex.RUnlock() } func (grid *Grid) AddChild(content Drawable) *GridCell { cell := &GridCell{ RowSpan: 1, ColSpan: 1, Content: content, } grid.mutex.Lock() grid.cells = append(grid.cells, cell) grid.mutex.Unlock() cell.Content.OnInvalidate(grid.cellInvalidated) cell.invalid.Store(true) grid.invalidateLayout() return cell } func (grid *Grid) RemoveChild(content Drawable) { grid.mutex.Lock() for i, cell := range grid.cells { if cell.Content == content { grid.cells = append(grid.cells[:i], grid.cells[i+1:]...) break } } grid.mutex.Unlock() grid.invalidateLayout() } func (grid *Grid) cellInvalidated(drawable Drawable) { var cell *GridCell grid.mutex.RLock() for _, cell = range grid.cells { if cell.Content == drawable { break } cell = nil } grid.mutex.RUnlock() if cell == nil { panic(fmt.Errorf("Attempted to invalidate unknown cell")) } cell.invalid.Store(true) grid.DoInvalidate(grid) }


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