Make grid sizes dynamic

The grid used static sizes which meant that changing settings didn't
have an effect on elements of the ui, notably the sidebar width. This
patch makes the `Size` parameter of a cell a function which returns the
`int`, allowing for dynamic sizes.

A `Const` function is also included for ease of use for static sizes.

1 files changed, 16 insertions, 10 deletions

diff --git a/lib/ui/grid.go b/lib/ui/grid.go
index b47c6bd..cff5577 100644
--- a/lib/ui/grid.go
+++ b/lib/ui/grid.go
@@ -31,10 +31,12 @@ const (
 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
+
+	// If Strategy = SIZE_EXACT, this function returns 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 the value returned by this function.
+	Size func() int
 }
 
 // Used to cache layout of each row/column
@@ -61,11 +63,11 @@ func NewGrid() *Grid {
 func MakeGrid(numRows, numCols, rowStrategy, colStrategy int) *Grid {
 	rows := make([]GridSpec, numRows)
 	for i := 0; i < numRows; i++ {
-		rows[i] = GridSpec{rowStrategy, 1}
+		rows[i] = GridSpec{rowStrategy, Const(1)}
 	}
 	cols := make([]GridSpec, numCols)
 	for i := 0; i < numCols; i++ {
-		cols[i] = GridSpec{colStrategy, 1}
+		cols[i] = GridSpec{colStrategy, Const(1)}
 	}
 	return NewGrid().Rows(rows).Columns(cols)
 }
@@ -191,10 +193,10 @@ func (grid *Grid) reflow(ctx *Context) {
 		nweights := 0
 		for _, spec := range *specs {
 			if spec.Strategy == SIZE_EXACT {
-				exact += spec.Size
+				exact += spec.Size()
 			} else if spec.Strategy == SIZE_WEIGHT {
 				nweights += 1
-				weight += spec.Size
+				weight += spec.Size()
 			}
 		}
 		offset := 0
@@ -205,9 +207,9 @@ func (grid *Grid) reflow(ctx *Context) {
 		for _, spec := range *specs {
 			layout := gridLayout{Offset: offset}
 			if spec.Strategy == SIZE_EXACT {
-				layout.Size = spec.Size
+				layout.Size = spec.Size()
 			} else if spec.Strategy == SIZE_WEIGHT {
-				proportion := float64(spec.Size) / float64(weight)
+				proportion := float64(spec.Size()) / float64(weight)
 				size := proportion * float64(extent-exact)
 				if remainingExact > 0 {
 					extraExact := int(math.Ceil(proportion * float64(remainingExact)))
@@ -284,3 +286,7 @@ func (grid *Grid) cellInvalidated(drawable Drawable) {
 	cell.invalid.Store(true)
 	grid.DoInvalidate(grid)
 }
+
+func Const(i int) func() int {
+	return func() int { return i }
+}