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package tview
import (
"math"
"github.com/gdamore/tcell"
)
// 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
// SetRows()/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 have its background color set to
// 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, set it to the desired color:
//
// grid.SetBackgroundColor(tview.Styles.PrimitiveBackgroundColor)
func NewGrid() *Grid {
g := &Grid{
Box: NewBox().SetBackgroundColor(tcell.ColorDefault),
bordersColor: Styles.GraphicsColor,
}
g.focus = g
return g
}
// SetRows defines how the rows of the grid are distributed. Each value defines
// the size of one row, starting with the leftmost row. Values greater 0
// represent absolute row widths (gaps not included). Values less or equal 0
// represent proportional row widths or fractions of the remaining free space,
// where 0 is treated the same as -1. That is, a row with a value of -3 will
// have three times the width of a row with a value of -1 (or 0). The minimum
// width set with SetMinSize() is always observed.
//
// Primitives may extend beyond the rows defined explicitly with this function.
// A value of 0 is assumed for any undefined row. In fact, if you never call
// this function, all rows occupied by primitives will have the same width.
// On the other hand, unoccupied rows 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 rows with widths of 30, 10, 15, 15, and 30
// cells:
//
// grid.SetRows(30, 10, -1, -1, -2)
//
// If a primitive were then placed in the 6th and 7th row, 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) SetRows(rows ...int) *Grid {
g.rows = rows
return g
}
// SetColumns defines how the columns of the grid are distributed. These values
// behave the same as the row values provided with SetRows(), see there for
// a definition and examples.
//
// The provided values correspond to column heights, the first value defining
// the height of the topmost column.
func (g *Grid) SetColumns(columns ...int) *Grid {
g.columns = columns
return g
}
// SetSize is a shortcut for SetRows() and SetColumns() where all row and column
// values are set to the given size values. See SetRows() 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 "width" rows and "height" columns. For
// example, for a primitive to occupy rows 2, 3, and 4 and columns 5 and 6:
//
// grid.AddItem(p, 2, 4, 3, 2, true)
//
// If width or height 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 that has at least one highest minimum value 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, height, width, minGridHeight, minGridWidth int, focus bool) *Grid {
g.items = append(g.items, &gridItem{
Item: p,
Row: row,
Column: column,
Height: height,
Width: width,
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 are 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.hasFocus = true
}
// Blur is called when this primitive loses focus.
func (g *Grid) Blur() {
g.hasFocus = false
}
// HasFocus returns whether or not this primitive has focus.
func (g *Grid) HasFocus() bool {
for _, item := range g.items {
if item.visible && item.Item.GetFocusable().HasFocus() {
return true
}
}
return g.hasFocus
}
// 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)) {
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++
}
})
}
// Draw draws this primitive onto the screen.
func (g *Grid) Draw(screen tcell.Screen) {
g.Box.Draw(screen)
x, y, width, height := g.GetInnerRect()
screenWidth, screenHeight := screen.Size()
// Make a list of items which apply.
items := make(map[Primitive]*gridItem)
for _, item := range g.items {
item.visible = false
if item.Width <= 0 || item.Height <= 0 || width < item.MinGridWidth || height < item.MinGridHeight {
continue
}
previousItem, ok := items[item.Item]
if ok && item.Width < previousItem.Width && item.Height < previousItem.Height {
continue
}
items[item.Item] = 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.
gridWidth := 0
gridHeight := 0
for index := 0; index < rows; index++ {
row := 0
if index < len(g.rows) {
row = g.rows[index]
}
if row > 0 {
if row < g.minHeight {
row = g.minHeight
}
gridHeight += row
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
gridHeight += rowAbs
}
for index := 0; index < columns; index++ {
column := 0
if index < len(g.columns) {
column = g.columns[index]
}
if column > 0 {
if column < g.minWidth {
column = g.minWidth
}
gridWidth += column
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
gridWidth += columnAbs
}
if g.borders {
gridHeight += rows + 1
gridWidth += columns + 1
} else {
gridHeight += (rows - 1) * g.gapRows
gridWidth += (columns - 1) * g.gapColumns
}
// Calculate row/column positions.
columnX, rowY := x, y
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 primitive, 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 primitive.GetFocusable().HasFocus() {
focus = item
}
}
// Calculate screen offsets.
var offsetX, offsetY, add int
if g.rowOffset < 0 {
g.rowOffset = 0
}
if g.columnOffset < 0 {
g.columnOffset = 0
}
if g.borders {
add = 1
}
for row := 0; row < rows-1; row++ {
remainingHeight := gridHeight - offsetY
if focus != nil && focus.y-add <= offsetY || // Don't let the focused item move out of screen.
row >= g.rowOffset && (focus == nil || focus != nil && focus.y-offsetY < height) || // We've reached the requested offset.
remainingHeight <= height { // We have enough space to show the rest.
if row > 0 {
if focus != nil && focus.y+focus.h+add-offsetY > height {
offsetY += focus.y + focus.h + add - offsetY - height
}
if remainingHeight < height {
offsetY = gridHeight - height
}
}
g.rowOffset = row
break
}
offsetY = rowPos[row+1] - add
}
for column := 0; column < columns-1; column++ {
remainingWidth := gridWidth - offsetX
if focus != nil && focus.x-add <= offsetX || // Don't let the focused item move out of screen.
column >= g.columnOffset && (focus == nil || focus != nil && focus.x-offsetX < width) || // We've reached the requested offset.
remainingWidth <= width { // We have enough space to show the rest.
if column > 0 {
if focus != nil && focus.x+focus.w+add-offsetX > width {
offsetX += focus.x + focus.w + add - offsetX - width
} else if remainingWidth < width {
offsetX = gridWidth - width
}
}
g.columnOffset = column
break
}
offsetX = columnPos[column+1] - add
}
// Draw primitives and borders.
for primitive, item := range items {
// Final primitive position.
if !item.visible {
continue
}
item.x -= offsetX
item.y -= offsetY
if item.x+item.w > x+width {
item.w = width - item.x
}
if item.y+item.h > y+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
}
primitive.SetRect(item.x, item.y, item.w, item.h)
// Draw primitive.
if item == focus {
defer primitive.Draw(screen)
} else {
primitive.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, g.bordersColor)
}
by = item.y + item.h
if by >= 0 && by < screenHeight {
PrintJoinedSemigraphics(screen, bx, by, Borders.Horizontal, g.bordersColor)
}
}
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, g.bordersColor)
}
bx = item.x + item.w
if bx >= 0 && bx < screenWidth {
PrintJoinedSemigraphics(screen, bx, by, Borders.Vertical, g.bordersColor)
}
}
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, g.bordersColor)
}
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, g.bordersColor)
}
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, g.bordersColor)
}
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, g.bordersColor)
}
}
}
}