gemini-browser

grid.go (20831B)

---

 package tview
 
 import (
 	"math"
 
 	"github.com/gdamore/tcell/v2"
 )
 
 // gridItem represents one primitive and its possible position on a grid.
 type gridItem struct {
 	Item                        Primitive // The item to be positioned. May be nil for an empty item.
 	Row, Column                 int       // The top-left grid cell where the item is placed.
 	Width, Height               int       // The number of rows and columns the item occupies.
 	MinGridWidth, MinGridHeight int       // The minimum grid width/height for which this item is visible.
 	Focus                       bool      // Whether or not this item attracts the layout's focus.
 
 	visible    bool // Whether or not this item was visible the last time the grid was drawn.
 	x, y, w, h int  // The last position of the item relative to the top-left corner of the grid. Undefined if visible is false.
 }
 
 // Grid is an implementation of a grid-based layout. It works by defining the
 // size of the rows and columns, then placing primitives into the grid.
 //
 // Some settings can lead to the grid exceeding its available space. SetOffset()
 // can then be used to scroll in steps of rows and columns. These offset values
 // can also be controlled with the arrow keys (or the "g","G", "j", "k", "h",
 // and "l" keys) while the grid has focus and none of its contained primitives
 // do.
 //
 // See https://github.com/rivo/tview/wiki/Grid for an example.
 type Grid struct {
 	*Box
 
 	// The items to be positioned.
 	items []*gridItem
 
 	// The definition of the rows and columns of the grid. See
 	// [Grid.SetRows] / [Grid.SetColumns] for details.
 	rows, columns []int
 
 	// The minimum sizes for rows and columns.
 	minWidth, minHeight int
 
 	// The size of the gaps between neighboring primitives. This is automatically
 	// set to 1 if borders is true.
 	gapRows, gapColumns int
 
 	// The number of rows and columns skipped before drawing the top-left corner
 	// of the grid.
 	rowOffset, columnOffset int
 
 	// Whether or not borders are drawn around grid items. If this is set to true,
 	// a gap size of 1 is automatically assumed (which is filled with the border
 	// graphics).
 	borders bool
 
 	// The color of the borders around grid items.
 	bordersColor tcell.Color
 }
 
 // NewGrid returns a new grid-based layout container with no initial primitives.
 //
 // Note that Box, the superclass of Grid, will be transparent so that any grid
 // areas not covered by any primitives will leave their background unchanged. To
 // clear a Grid's background before any items are drawn, reset its Box to one
 // with the desired color:
 //
 //	grid.Box = NewBox()
 func NewGrid() *Grid {
 	g := &Grid{
 		bordersColor: Styles.GraphicsColor,
 	}
 	g.Box = NewBox()
 	g.Box.dontClear = true
 	return g
 }
 
 // SetColumns defines how the columns of the grid are distributed. Each value
 // defines the size of one column, starting with the leftmost column. Values
 // greater than 0 represent absolute column widths (gaps not included). Values
 // less than or equal to 0 represent proportional column widths or fractions of
 // the remaining free space, where 0 is treated the same as -1. That is, a
 // column with a value of -3 will have three times the width of a column with a
 // value of -1 (or 0). The minimum width set with SetMinSize() is always
 // observed.
 //
 // Primitives may extend beyond the columns defined explicitly with this
 // function. A value of 0 is assumed for any undefined column. In fact, if you
 // never call this function, all columns occupied by primitives will have the
 // same width. On the other hand, unoccupied columns defined with this function
 // will always take their place.
 //
 // Assuming a total width of the grid of 100 cells and a minimum width of 0, the
 // following call will result in columns with widths of 30, 10, 15, 15, and 30
 // cells:
 //
 //	grid.SetColumns(30, 10, -1, -1, -2)
 //
 // If a primitive were then placed in the 6th and 7th column, the resulting
 // widths would be: 30, 10, 10, 10, 20, 10, and 10 cells.
 //
 // If you then called SetMinSize() as follows:
 //
 //	grid.SetMinSize(15, 20)
 //
 // The resulting widths would be: 30, 15, 15, 15, 20, 15, and 15 cells, a total
 // of 125 cells, 25 cells wider than the available grid width.
 func (g *Grid) SetColumns(columns ...int) *Grid {
 	g.columns = columns
 	return g
 }
 
 // SetRows defines how the rows of the grid are distributed. These values behave
 // the same as the column values provided with [Grid.SetColumns], see there
 // for a definition and examples.
 //
 // The provided values correspond to row heights, the first value defining
 // the height of the topmost row.
 func (g *Grid) SetRows(rows ...int) *Grid {
 	g.rows = rows
 	return g
 }
 
 // SetSize is a shortcut for [Grid.SetRows] and [Grid.SetColumns] where
 // all row and column values are set to the given size values. See
 // [Grid.SetColumns] for details on sizes.
 func (g *Grid) SetSize(numRows, numColumns, rowSize, columnSize int) *Grid {
 	g.rows = make([]int, numRows)
 	for index := range g.rows {
 		g.rows[index] = rowSize
 	}
 	g.columns = make([]int, numColumns)
 	for index := range g.columns {
 		g.columns[index] = columnSize
 	}
 	return g
 }
 
 // SetMinSize sets an absolute minimum width for rows and an absolute minimum
 // height for columns. Panics if negative values are provided.
 func (g *Grid) SetMinSize(row, column int) *Grid {
 	if row < 0 || column < 0 {
 		panic("Invalid minimum row/column size")
 	}
 	g.minHeight, g.minWidth = row, column
 	return g
 }
 
 // SetGap sets the size of the gaps between neighboring primitives on the grid.
 // If borders are drawn (see SetBorders()), these values are ignored and a gap
 // of 1 is assumed. Panics if negative values are provided.
 func (g *Grid) SetGap(row, column int) *Grid {
 	if row < 0 || column < 0 {
 		panic("Invalid gap size")
 	}
 	g.gapRows, g.gapColumns = row, column
 	return g
 }
 
 // SetBorders sets whether or not borders are drawn around grid items. Setting
 // this value to true will cause the gap values (see SetGap()) to be ignored and
 // automatically assumed to be 1 where the border graphics are drawn.
 func (g *Grid) SetBorders(borders bool) *Grid {
 	g.borders = borders
 	return g
 }
 
 // SetBordersColor sets the color of the item borders.
 func (g *Grid) SetBordersColor(color tcell.Color) *Grid {
 	g.bordersColor = color
 	return g
 }
 
 // AddItem adds a primitive and its position to the grid. The top-left corner
 // of the primitive will be located in the top-left corner of the grid cell at
 // the given row and column and will span "rowSpan" rows and "colSpan" columns.
 // For example, for a primitive to occupy rows 2, 3, and 4 and columns 5 and 6:
 //
 //	grid.AddItem(p, 2, 5, 3, 2, 0, 0, true)
 //
 // If rowSpan or colSpan is 0, the primitive will not be drawn.
 //
 // You can add the same primitive multiple times with different grid positions.
 // The minGridWidth and minGridHeight values will then determine which of those
 // positions will be used. This is similar to CSS media queries. These minimum
 // values refer to the overall size of the grid. If multiple items for the same
 // primitive apply, the one with the highest minimum value (width or height,
 // whatever is higher) will be used, or the primitive added last if those values
 // are the same. Example:
 //
 //	grid.AddItem(p, 0, 0, 0, 0, 0, 0, true). // Hide in small grids.
 //	  AddItem(p, 0, 0, 1, 2, 100, 0, true).  // One-column layout for medium grids.
 //	  AddItem(p, 1, 1, 3, 2, 300, 0, true)   // Multi-column layout for large grids.
 //
 // To use the same grid layout for all sizes, simply set minGridWidth and
 // minGridHeight to 0.
 //
 // If the item's focus is set to true, it will receive focus when the grid
 // receives focus. If there are multiple items with a true focus flag, the last
 // visible one that was added will receive focus.
 func (g *Grid) AddItem(p Primitive, row, column, rowSpan, colSpan, minGridHeight, minGridWidth int, focus bool) *Grid {
 	g.items = append(g.items, &gridItem{
 		Item:          p,
 		Row:           row,
 		Column:        column,
 		Height:        rowSpan,
 		Width:         colSpan,
 		MinGridHeight: minGridHeight,
 		MinGridWidth:  minGridWidth,
 		Focus:         focus,
 	})
 	return g
 }
 
 // RemoveItem removes all items for the given primitive from the grid, keeping
 // the order of the remaining items intact.
 func (g *Grid) RemoveItem(p Primitive) *Grid {
 	for index := len(g.items) - 1; index >= 0; index-- {
 		if g.items[index].Item == p {
 			g.items = append(g.items[:index], g.items[index+1:]...)
 		}
 	}
 	return g
 }
 
 // Clear removes all items from the grid.
 func (g *Grid) Clear() *Grid {
 	g.items = nil
 	return g
 }
 
 // SetOffset sets the number of rows and columns which are skipped before
 // drawing the first grid cell in the top-left corner. As the grid will never
 // completely move off the screen, these values may be adjusted the next time
 // the grid is drawn. The actual position of the grid may also be adjusted such
 // that contained primitives that have focus remain visible.
 func (g *Grid) SetOffset(rows, columns int) *Grid {
 	g.rowOffset, g.columnOffset = rows, columns
 	return g
 }
 
 // GetOffset returns the current row and column offset (see SetOffset() for
 // details).
 func (g *Grid) GetOffset() (rows, columns int) {
 	return g.rowOffset, g.columnOffset
 }
 
 // Focus is called when this primitive receives focus.
 func (g *Grid) Focus(delegate func(p Primitive)) {
 	for _, item := range g.items {
 		if item.Focus {
 			delegate(item.Item)
 			return
 		}
 	}
 	g.Box.Focus(delegate)
 }
 
 // HasFocus returns whether or not this primitive has focus.
 func (g *Grid) HasFocus() bool {
 	for _, item := range g.items {
 		if item.visible && item.Item.HasFocus() {
 			return true
 		}
 	}
 	return g.Box.HasFocus()
 }
 
 // Draw draws this primitive onto the screen.
 func (g *Grid) Draw(screen tcell.Screen) {
 	g.Box.DrawForSubclass(screen, g)
 	x, y, width, height := g.GetInnerRect()
 	screenWidth, screenHeight := screen.Size()
 
 	// Make a list of items which apply.
 	items := make([]*gridItem, 0, len(g.items))
 ItemLoop:
 	for _, item := range g.items {
 		item.visible = false
 		if item.Item == nil || item.Width <= 0 || item.Height <= 0 || width < item.MinGridWidth || height < item.MinGridHeight {
 			continue // Disqualified.
 		}
 
 		// Check for overlaps and multiple layouts of the same item.
 		for index, existing := range items {
 			// Do they overlap or are identical?
 			if item.Item != existing.Item &&
 				(item.Row >= existing.Row+existing.Height || item.Row+item.Height <= existing.Row ||
 					item.Column >= existing.Column+existing.Width || item.Column+item.Width <= existing.Column) {
 				continue // They don't and aren't.
 			}
 
 			// What's their minimum size?
 			itemMin := item.MinGridWidth
 			if item.MinGridHeight > itemMin {
 				itemMin = item.MinGridHeight
 			}
 			existingMin := existing.MinGridWidth
 			if existing.MinGridHeight > existingMin {
 				existingMin = existing.MinGridHeight
 			}
 
 			// Which one is more important?
 			if itemMin < existingMin {
 				continue ItemLoop // This one isn't. Drop it.
 			}
 			items[index] = item // This one is. Replace the other.
 			continue ItemLoop
 		}
 
 		// This item will be visible.
 		items = append(items, item)
 	}
 
 	// How many rows and columns do we have?
 	rows := len(g.rows)
 	columns := len(g.columns)
 	for _, item := range items {
 		rowEnd := item.Row + item.Height
 		if rowEnd > rows {
 			rows = rowEnd
 		}
 		columnEnd := item.Column + item.Width
 		if columnEnd > columns {
 			columns = columnEnd
 		}
 	}
 	if rows == 0 || columns == 0 {
 		return // No content.
 	}
 
 	// Where are they located?
 	rowPos := make([]int, rows)
 	rowHeight := make([]int, rows)
 	columnPos := make([]int, columns)
 	columnWidth := make([]int, columns)
 
 	// How much space do we distribute?
 	remainingWidth := width
 	remainingHeight := height
 	proportionalWidth := 0
 	proportionalHeight := 0
 	for index, row := range g.rows {
 		if row > 0 {
 			if row < g.minHeight {
 				row = g.minHeight
 			}
 			remainingHeight -= row
 			rowHeight[index] = row
 		} else if row == 0 {
 			proportionalHeight++
 		} else {
 			proportionalHeight += -row
 		}
 	}
 	for index, column := range g.columns {
 		if column > 0 {
 			if column < g.minWidth {
 				column = g.minWidth
 			}
 			remainingWidth -= column
 			columnWidth[index] = column
 		} else if column == 0 {
 			proportionalWidth++
 		} else {
 			proportionalWidth += -column
 		}
 	}
 	if g.borders {
 		remainingHeight -= rows + 1
 		remainingWidth -= columns + 1
 	} else {
 		remainingHeight -= (rows - 1) * g.gapRows
 		remainingWidth -= (columns - 1) * g.gapColumns
 	}
 	if rows > len(g.rows) {
 		proportionalHeight += rows - len(g.rows)
 	}
 	if columns > len(g.columns) {
 		proportionalWidth += columns - len(g.columns)
 	}
 
 	// Distribute proportional rows/columns.
 	for index := 0; index < rows; index++ {
 		row := 0
 		if index < len(g.rows) {
 			row = g.rows[index]
 		}
 		if row > 0 {
 			continue // Not proportional. We already know the width.
 		} else if row == 0 {
 			row = 1
 		} else {
 			row = -row
 		}
 		rowAbs := row * remainingHeight / proportionalHeight
 		remainingHeight -= rowAbs
 		proportionalHeight -= row
 		if rowAbs < g.minHeight {
 			rowAbs = g.minHeight
 		}
 		rowHeight[index] = rowAbs
 	}
 	for index := 0; index < columns; index++ {
 		column := 0
 		if index < len(g.columns) {
 			column = g.columns[index]
 		}
 		if column > 0 {
 			continue // Not proportional. We already know the height.
 		} else if column == 0 {
 			column = 1
 		} else {
 			column = -column
 		}
 		columnAbs := column * remainingWidth / proportionalWidth
 		remainingWidth -= columnAbs
 		proportionalWidth -= column
 		if columnAbs < g.minWidth {
 			columnAbs = g.minWidth
 		}
 		columnWidth[index] = columnAbs
 	}
 
 	// Calculate row/column positions.
 	var columnX, rowY int
 	if g.borders {
 		columnX++
 		rowY++
 	}
 	for index, row := range rowHeight {
 		rowPos[index] = rowY
 		gap := g.gapRows
 		if g.borders {
 			gap = 1
 		}
 		rowY += row + gap
 	}
 	for index, column := range columnWidth {
 		columnPos[index] = columnX
 		gap := g.gapColumns
 		if g.borders {
 			gap = 1
 		}
 		columnX += column + gap
 	}
 
 	// Calculate primitive positions.
 	var focus *gridItem // The item which has focus.
 	for _, item := range items {
 		px := columnPos[item.Column]
 		py := rowPos[item.Row]
 		var pw, ph int
 		for index := 0; index < item.Height; index++ {
 			ph += rowHeight[item.Row+index]
 		}
 		for index := 0; index < item.Width; index++ {
 			pw += columnWidth[item.Column+index]
 		}
 		if g.borders {
 			pw += item.Width - 1
 			ph += item.Height - 1
 		} else {
 			pw += (item.Width - 1) * g.gapColumns
 			ph += (item.Height - 1) * g.gapRows
 		}
 		item.x, item.y, item.w, item.h = px, py, pw, ph
 		item.visible = true
 		if item.Item.HasFocus() {
 			focus = item
 		}
 	}
 
 	// Calculate screen offsets.
 	var offsetX, offsetY int
 	add := 1
 	if !g.borders {
 		add = g.gapRows
 	}
 	for index, height := range rowHeight {
 		if index >= g.rowOffset {
 			break
 		}
 		offsetY += height + add
 	}
 	if !g.borders {
 		add = g.gapColumns
 	}
 	for index, width := range columnWidth {
 		if index >= g.columnOffset {
 			break
 		}
 		offsetX += width + add
 	}
 
 	// The focused item must be within the visible area.
 	if focus != nil {
 		if focus.y+focus.h-offsetY >= height {
 			offsetY = focus.y - height + focus.h
 		}
 		if focus.y-offsetY < 0 {
 			offsetY = focus.y
 		}
 		if focus.x+focus.w-offsetX >= width {
 			offsetX = focus.x - width + focus.w
 		}
 		if focus.x-offsetX < 0 {
 			offsetX = focus.x
 		}
 	}
 
 	// Adjust row/column offsets based on this value.
 	var from, to int
 	for index, pos := range rowPos {
 		if pos-offsetY < 0 {
 			from = index + 1
 		}
 		if pos-offsetY < height {
 			to = index
 		}
 	}
 	if g.rowOffset < from {
 		g.rowOffset = from
 	}
 	if g.rowOffset > to {
 		g.rowOffset = to
 	}
 	from, to = 0, 0
 	for index, pos := range columnPos {
 		if pos-offsetX < 0 {
 			from = index + 1
 		}
 		if pos-offsetX < width {
 			to = index
 		}
 	}
 	if g.columnOffset < from {
 		g.columnOffset = from
 	}
 	if g.columnOffset > to {
 		g.columnOffset = to
 	}
 
 	// Draw primitives and borders.
 	borderStyle := tcell.StyleDefault.Background(g.backgroundColor).Foreground(g.bordersColor)
 	for _, item := range items {
 		// Final primitive position.
 		if !item.visible {
 			continue
 		}
 		item.x -= offsetX
 		item.y -= offsetY
 		if item.x >= width || item.x+item.w <= 0 || item.y >= height || item.y+item.h <= 0 {
 			item.visible = false
 			continue
 		}
 		if item.x+item.w > width {
 			item.w = width - item.x
 		}
 		if item.y+item.h > height {
 			item.h = height - item.y
 		}
 		if item.x < 0 {
 			item.w += item.x
 			item.x = 0
 		}
 		if item.y < 0 {
 			item.h += item.y
 			item.y = 0
 		}
 		if item.w <= 0 || item.h <= 0 {
 			item.visible = false
 			continue
 		}
 		item.x += x
 		item.y += y
 		item.Item.SetRect(item.x, item.y, item.w, item.h)
 
 		// Draw primitive.
 		if item == focus {
 			defer item.Item.Draw(screen)
 		} else {
 			item.Item.Draw(screen)
 		}
 
 		// Draw border around primitive.
 		if g.borders {
 			for bx := item.x; bx < item.x+item.w; bx++ { // Top/bottom lines.
 				if bx < 0 || bx >= screenWidth {
 					continue
 				}
 				by := item.y - 1
 				if by >= 0 && by < screenHeight {
 					PrintJoinedSemigraphics(screen, bx, by, Borders.Horizontal, borderStyle)
 				}
 				by = item.y + item.h
 				if by >= 0 && by < screenHeight {
 					PrintJoinedSemigraphics(screen, bx, by, Borders.Horizontal, borderStyle)
 				}
 			}
 			for by := item.y; by < item.y+item.h; by++ { // Left/right lines.
 				if by < 0 || by >= screenHeight {
 					continue
 				}
 				bx := item.x - 1
 				if bx >= 0 && bx < screenWidth {
 					PrintJoinedSemigraphics(screen, bx, by, Borders.Vertical, borderStyle)
 				}
 				bx = item.x + item.w
 				if bx >= 0 && bx < screenWidth {
 					PrintJoinedSemigraphics(screen, bx, by, Borders.Vertical, borderStyle)
 				}
 			}
 			bx, by := item.x-1, item.y-1 // Top-left corner.
 			if bx >= 0 && bx < screenWidth && by >= 0 && by < screenHeight {
 				PrintJoinedSemigraphics(screen, bx, by, Borders.TopLeft, borderStyle)
 			}
 			bx, by = item.x+item.w, item.y-1 // Top-right corner.
 			if bx >= 0 && bx < screenWidth && by >= 0 && by < screenHeight {
 				PrintJoinedSemigraphics(screen, bx, by, Borders.TopRight, borderStyle)
 			}
 			bx, by = item.x-1, item.y+item.h // Bottom-left corner.
 			if bx >= 0 && bx < screenWidth && by >= 0 && by < screenHeight {
 				PrintJoinedSemigraphics(screen, bx, by, Borders.BottomLeft, borderStyle)
 			}
 			bx, by = item.x+item.w, item.y+item.h // Bottom-right corner.
 			if bx >= 0 && bx < screenWidth && by >= 0 && by < screenHeight {
 				PrintJoinedSemigraphics(screen, bx, by, Borders.BottomRight, borderStyle)
 			}
 		}
 	}
 }
 
 // MouseHandler returns the mouse handler for this primitive.
 func (g *Grid) MouseHandler() func(action MouseAction, event *tcell.EventMouse, setFocus func(p Primitive)) (consumed bool, capture Primitive) {
 	return g.WrapMouseHandler(func(action MouseAction, event *tcell.EventMouse, setFocus func(p Primitive)) (consumed bool, capture Primitive) {
 		if !g.InRect(event.Position()) {
 			return false, nil
 		}
 
 		// Pass mouse events along to the first child item that takes it.
 		for _, item := range g.items {
 			if item.Item == nil {
 				continue
 			}
 			consumed, capture = item.Item.MouseHandler()(action, event, setFocus)
 			if consumed {
 				return
 			}
 		}
 
 		return
 	})
 }
 
 // InputHandler returns the handler for this primitive.
 func (g *Grid) InputHandler() func(event *tcell.EventKey, setFocus func(p Primitive)) {
 	return g.WrapInputHandler(func(event *tcell.EventKey, setFocus func(p Primitive)) {
 		if !g.hasFocus {
 			// Pass event on to child primitive.
 			for _, item := range g.items {
 				if item != nil && item.Item.HasFocus() {
 					if handler := item.Item.InputHandler(); handler != nil {
 						handler(event, setFocus)
 						return
 					}
 				}
 			}
 			return
 		}
 
 		// Process our own key events if we have direct focus.
 		switch event.Key() {
 		case tcell.KeyRune:
 			switch event.Rune() {
 			case 'g':
 				g.rowOffset, g.columnOffset = 0, 0
 			case 'G':
 				g.rowOffset = math.MaxInt32
 			case 'j':
 				g.rowOffset++
 			case 'k':
 				g.rowOffset--
 			case 'h':
 				g.columnOffset--
 			case 'l':
 				g.columnOffset++
 			}
 		case tcell.KeyHome:
 			g.rowOffset, g.columnOffset = 0, 0
 		case tcell.KeyEnd:
 			g.rowOffset = math.MaxInt32
 		case tcell.KeyUp:
 			g.rowOffset--
 		case tcell.KeyDown:
 			g.rowOffset++
 		case tcell.KeyLeft:
 			g.columnOffset--
 		case tcell.KeyRight:
 			g.columnOffset++
 		}
 	})
 }
 
 // PasteHandler returns the handler for this primitive.
 func (g *Grid) PasteHandler() func(pastedText string, setFocus func(p Primitive)) {
 	return g.WrapPasteHandler(func(pastedText string, setFocus func(p Primitive)) {
 		for _, item := range g.items {
 			if item != nil && item.Item.HasFocus() {
 				if handler := item.Item.PasteHandler(); handler != nil {
 					handler(pastedText, setFocus)
 					return
 				}
 			}
 		}
 	})
 }