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.

7 files changed, 115 insertions, 109 deletions

diff --git a/commands/set.go b/commands/set.go
index 1d20f06..cc6333e 100644
--- a/commands/set.go
+++ b/commands/set.go
@@ -61,6 +61,9 @@ func SetCore(aerc *widgets.Aerc, args []string) error {
 		return err
 	}
 
+	// ensure any ui changes take effect
+	aerc.Invalidate()
+
 	return nil
 }
 
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 }
+}
diff --git a/widgets/account-wizard.go b/widgets/account-wizard.go
index 6f93367..4e51926 100644
--- a/widgets/account-wizard.go
+++ b/widgets/account-wizard.go
@@ -136,18 +136,18 @@ func NewAccountWizard(conf *config.AercConfig, aerc *Aerc) *AccountWizard {
 	})
 
 	basics := ui.NewGrid().Rows([]ui.GridSpec{
-		{ui.SIZE_EXACT, 8}, // Introduction
-		{ui.SIZE_EXACT, 1}, // Account name (label)
-		{ui.SIZE_EXACT, 1}, // (input)
-		{ui.SIZE_EXACT, 1}, // Padding
-		{ui.SIZE_EXACT, 1}, // Full name (label)
-		{ui.SIZE_EXACT, 1}, // (input)
-		{ui.SIZE_EXACT, 1}, // Padding
-		{ui.SIZE_EXACT, 1}, // Email address (label)
-		{ui.SIZE_EXACT, 1}, // (input)
-		{ui.SIZE_WEIGHT, 1},
+		{ui.SIZE_EXACT, ui.Const(8)}, // Introduction
+		{ui.SIZE_EXACT, ui.Const(1)}, // Account name (label)
+		{ui.SIZE_EXACT, ui.Const(1)}, // (input)
+		{ui.SIZE_EXACT, ui.Const(1)}, // Padding
+		{ui.SIZE_EXACT, ui.Const(1)}, // Full name (label)
+		{ui.SIZE_EXACT, ui.Const(1)}, // (input)
+		{ui.SIZE_EXACT, ui.Const(1)}, // Padding
+		{ui.SIZE_EXACT, ui.Const(1)}, // Email address (label)
+		{ui.SIZE_EXACT, ui.Const(1)}, // (input)
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	}).Columns([]ui.GridSpec{
-		{ui.SIZE_WEIGHT, 1},
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	})
 	basics.AddChild(
 		ui.NewText("\nWelcome to aerc! Let's configure your account.\n\n" +
@@ -209,23 +209,23 @@ func NewAccountWizard(conf *config.AercConfig, aerc *Aerc) *AccountWizard {
 	})
 
 	incoming := ui.NewGrid().Rows([]ui.GridSpec{
-		{ui.SIZE_EXACT, 3}, // Introduction
-		{ui.SIZE_EXACT, 1}, // Username (label)
-		{ui.SIZE_EXACT, 1}, // (input)
-		{ui.SIZE_EXACT, 1}, // Padding
-		{ui.SIZE_EXACT, 1}, // Password (label)
-		{ui.SIZE_EXACT, 1}, // (input)
-		{ui.SIZE_EXACT, 1}, // Padding
-		{ui.SIZE_EXACT, 1}, // Server (label)
-		{ui.SIZE_EXACT, 1}, // (input)
-		{ui.SIZE_EXACT, 1}, // Padding
-		{ui.SIZE_EXACT, 1}, // Connection mode (label)
-		{ui.SIZE_EXACT, 2}, // (input)
-		{ui.SIZE_EXACT, 1}, // Padding
-		{ui.SIZE_EXACT, 1}, // Connection string
-		{ui.SIZE_WEIGHT, 1},
+		{ui.SIZE_EXACT, ui.Const(3)}, // Introduction
+		{ui.SIZE_EXACT, ui.Const(1)}, // Username (label)
+		{ui.SIZE_EXACT, ui.Const(1)}, // (input)
+		{ui.SIZE_EXACT, ui.Const(1)}, // Padding
+		{ui.SIZE_EXACT, ui.Const(1)}, // Password (label)
+		{ui.SIZE_EXACT, ui.Const(1)}, // (input)
+		{ui.SIZE_EXACT, ui.Const(1)}, // Padding
+		{ui.SIZE_EXACT, ui.Const(1)}, // Server (label)
+		{ui.SIZE_EXACT, ui.Const(1)}, // (input)
+		{ui.SIZE_EXACT, ui.Const(1)}, // Padding
+		{ui.SIZE_EXACT, ui.Const(1)}, // Connection mode (label)
+		{ui.SIZE_EXACT, ui.Const(2)}, // (input)
+		{ui.SIZE_EXACT, ui.Const(1)}, // Padding
+		{ui.SIZE_EXACT, ui.Const(1)}, // Connection string
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	}).Columns([]ui.GridSpec{
-		{ui.SIZE_WEIGHT, 1},
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	})
 	incoming.AddChild(ui.NewText("\nConfigure incoming mail (IMAP)"))
 	incoming.AddChild(
@@ -283,26 +283,26 @@ func NewAccountWizard(conf *config.AercConfig, aerc *Aerc) *AccountWizard {
 	})
 
 	outgoing := ui.NewGrid().Rows([]ui.GridSpec{
-		{ui.SIZE_EXACT, 3}, // Introduction
-		{ui.SIZE_EXACT, 1}, // Username (label)
-		{ui.SIZE_EXACT, 1}, // (input)
-		{ui.SIZE_EXACT, 1}, // Padding
-		{ui.SIZE_EXACT, 1}, // Password (label)
-		{ui.SIZE_EXACT, 1}, // (input)
-		{ui.SIZE_EXACT, 1}, // Padding
-		{ui.SIZE_EXACT, 1}, // Server (label)
-		{ui.SIZE_EXACT, 1}, // (input)
-		{ui.SIZE_EXACT, 1}, // Padding
-		{ui.SIZE_EXACT, 1}, // Connection mode (label)
-		{ui.SIZE_EXACT, 2}, // (input)
-		{ui.SIZE_EXACT, 1}, // Padding
-		{ui.SIZE_EXACT, 1}, // Connection string
-		{ui.SIZE_EXACT, 1}, // Padding
-		{ui.SIZE_EXACT, 1}, // Copy to sent (label)
-		{ui.SIZE_EXACT, 2}, // (input)
-		{ui.SIZE_WEIGHT, 1},
+		{ui.SIZE_EXACT, ui.Const(3)}, // Introduction
+		{ui.SIZE_EXACT, ui.Const(1)}, // Username (label)
+		{ui.SIZE_EXACT, ui.Const(1)}, // (input)
+		{ui.SIZE_EXACT, ui.Const(1)}, // Padding
+		{ui.SIZE_EXACT, ui.Const(1)}, // Password (label)
+		{ui.SIZE_EXACT, ui.Const(1)}, // (input)
+		{ui.SIZE_EXACT, ui.Const(1)}, // Padding
+		{ui.SIZE_EXACT, ui.Const(1)}, // Server (label)
+		{ui.SIZE_EXACT, ui.Const(1)}, // (input)
+		{ui.SIZE_EXACT, ui.Const(1)}, // Padding
+		{ui.SIZE_EXACT, ui.Const(1)}, // Connection mode (label)
+		{ui.SIZE_EXACT, ui.Const(2)}, // (input)
+		{ui.SIZE_EXACT, ui.Const(1)}, // Padding
+		{ui.SIZE_EXACT, ui.Const(1)}, // Connection string
+		{ui.SIZE_EXACT, ui.Const(1)}, // Padding
+		{ui.SIZE_EXACT, ui.Const(1)}, // Copy to sent (label)
+		{ui.SIZE_EXACT, ui.Const(2)}, // (input)
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	}).Columns([]ui.GridSpec{
-		{ui.SIZE_WEIGHT, 1},
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	})
 	outgoing.AddChild(ui.NewText("\nConfigure outgoing mail (SMTP)"))
 	outgoing.AddChild(
@@ -374,10 +374,10 @@ func NewAccountWizard(conf *config.AercConfig, aerc *Aerc) *AccountWizard {
 	})
 
 	complete := ui.NewGrid().Rows([]ui.GridSpec{
-		{ui.SIZE_EXACT, 7},  // Introduction
-		{ui.SIZE_WEIGHT, 1}, // Previous / Finish / Finish & open tutorial
+		{ui.SIZE_EXACT, ui.Const(7)},  // Introduction
+		{ui.SIZE_WEIGHT, ui.Const(1)}, // Previous / Finish / Finish & open tutorial
 	}).Columns([]ui.GridSpec{
-		{ui.SIZE_WEIGHT, 1},
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	})
 	complete.AddChild(ui.NewText(
 		"\nConfiguration complete!\n\n" +
diff --git a/widgets/account.go b/widgets/account.go
index 20ed345..313a364 100644
--- a/widgets/account.go
+++ b/widgets/account.go
@@ -45,45 +45,38 @@ func NewAccountView(aerc *Aerc, conf *config.AercConfig, acct *config.AccountCon
 		config.UI_CONTEXT_ACCOUNT: acct.Name,
 	})
 
-	grid := ui.NewGrid().Rows([]ui.GridSpec{
-		{ui.SIZE_WEIGHT, 1},
+	view := &AccountView{
+		acct:   acct,
+		aerc:   aerc,
+		conf:   conf,
+		host:   host,
+		logger: logger,
+	}
+
+	view.grid = ui.NewGrid().Rows([]ui.GridSpec{
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	}).Columns([]ui.GridSpec{
-		{ui.SIZE_EXACT, acctUiConf.SidebarWidth},
-		{ui.SIZE_WEIGHT, 1},
+		{ui.SIZE_EXACT, func() int {
+			return view.UiConfig().SidebarWidth
+		}},
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	})
 
 	worker, err := worker.NewWorker(acct.Source, logger)
 	if err != nil {
 		host.SetStatus(fmt.Sprintf("%s: %s", acct.Name, err)).
 			Color(tcell.ColorDefault, tcell.ColorRed)
-		return &AccountView{
-			acct:   acct,
-			aerc:   aerc,
-			grid:   grid,
-			host:   host,
-			logger: logger,
-		}
+		return view
 	}
+	view.worker = worker
 
-	dirlist := NewDirectoryList(conf, acct, logger, worker)
+	view.dirlist = NewDirectoryList(conf, acct, logger, worker)
 	if acctUiConf.SidebarWidth > 0 {
-		grid.AddChild(ui.NewBordered(dirlist, ui.BORDER_RIGHT))
+		view.grid.AddChild(ui.NewBordered(view.dirlist, ui.BORDER_RIGHT))
 	}
 
-	msglist := NewMessageList(conf, logger, aerc)
-	grid.AddChild(msglist).At(0, 1)
-
-	view := &AccountView{
-		acct:    acct,
-		aerc:    aerc,
-		conf:    conf,
-		dirlist: dirlist,
-		grid:    grid,
-		host:    host,
-		logger:  logger,
-		msglist: msglist,
-		worker:  worker,
-	}
+	view.msglist = NewMessageList(conf, logger, aerc)
+	view.grid.AddChild(view.msglist).At(0, 1)
 
 	go worker.Backend.Run()
 
diff --git a/widgets/aerc.go b/widgets/aerc.go
index 829873a..4913be3 100644
--- a/widgets/aerc.go
+++ b/widgets/aerc.go
@@ -56,11 +56,11 @@ func NewAerc(conf *config.AercConfig, logger *log.Logger,
 	statusbar.Push(statusline)
 
 	grid := ui.NewGrid().Rows([]ui.GridSpec{
-		{ui.SIZE_EXACT, 1},
-		{ui.SIZE_WEIGHT, 1},
-		{ui.SIZE_EXACT, 1},
+		{ui.SIZE_EXACT, ui.Const(1)},
+		{ui.SIZE_WEIGHT, ui.Const(1)},
+		{ui.SIZE_EXACT, ui.Const(1)},
 	}).Columns([]ui.GridSpec{
-		{ui.SIZE_WEIGHT, 1},
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	})
 	grid.AddChild(tabs.TabStrip)
 	grid.AddChild(tabs.TabContent).At(1, 0)
@@ -552,7 +552,6 @@ func (aerc *Aerc) CloseDialog() {
 	return
 }
 
-
 func (aerc *Aerc) GetPassword(title string, prompt string) (chText chan string, chErr chan error) {
 	chText = make(chan string, 1)
 	chErr = make(chan error, 1)
diff --git a/widgets/compose.go b/widgets/compose.go
index 01b8dd8..b68c406 100644
--- a/widgets/compose.go
+++ b/widgets/compose.go
@@ -673,13 +673,15 @@ func (c *Composer) updateGrid() {
 	)
 
 	if c.grid == nil {
-		c.grid = ui.NewGrid().Columns([]ui.GridSpec{{ui.SIZE_WEIGHT, 1}})
+		c.grid = ui.NewGrid().Columns([]ui.GridSpec{
+			{ui.SIZE_WEIGHT, ui.Const(1)},
+		})
 	}
 
 	c.grid.Rows([]ui.GridSpec{
-		{ui.SIZE_EXACT, height},
-		{ui.SIZE_EXACT, 1},
-		{ui.SIZE_WEIGHT, 1},
+		{ui.SIZE_EXACT, ui.Const(height)},
+		{ui.SIZE_EXACT, ui.Const(1)},
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	})
 
 	if c.header != nil {
@@ -768,15 +770,18 @@ type reviewMessage struct {
 }
 
 func newReviewMessage(composer *Composer, err error) *reviewMessage {
-	spec := []ui.GridSpec{{ui.SIZE_EXACT, 2}, {ui.SIZE_EXACT, 1}}
+	spec := []ui.GridSpec{
+		{ui.SIZE_EXACT, ui.Const(2)},
+		{ui.SIZE_EXACT, ui.Const(1)},
+	}
 	for i := 0; i < len(composer.attachments)-1; i++ {
-		spec = append(spec, ui.GridSpec{ui.SIZE_EXACT, 1})
+		spec = append(spec, ui.GridSpec{ui.SIZE_EXACT, ui.Const(1)})
 	}
 	// make the last element fill remaining space
-	spec = append(spec, ui.GridSpec{ui.SIZE_WEIGHT, 1})
+	spec = append(spec, ui.GridSpec{ui.SIZE_WEIGHT, ui.Const(1)})
 
 	grid := ui.NewGrid().Rows(spec).Columns([]ui.GridSpec{
-		{ui.SIZE_WEIGHT, 1},
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	})
 
 	if err != nil {
diff --git a/widgets/msgviewer.go b/widgets/msgviewer.go
index ce85970..f06b787 100644
--- a/widgets/msgviewer.go
+++ b/widgets/msgviewer.go
@@ -69,7 +69,7 @@ func NewMessageViewer(acct *AccountView,
 	)
 
 	rows := []ui.GridSpec{
-		{ui.SIZE_EXACT, headerHeight},
+		{ui.SIZE_EXACT, ui.Const(headerHeight)},
 	}
 
 	if msg.PGPDetails() != nil {
@@ -77,16 +77,16 @@ func NewMessageViewer(acct *AccountView,
 		if msg.PGPDetails().IsSigned && msg.PGPDetails().IsEncrypted {
 			height = 2
 		}
-		rows = append(rows, ui.GridSpec{ui.SIZE_EXACT, height})
+		rows = append(rows, ui.GridSpec{ui.SIZE_EXACT, ui.Const(height)})
 	}
 
 	rows = append(rows, []ui.GridSpec{
-		{ui.SIZE_EXACT, 1},
-		{ui.SIZE_WEIGHT, 1},
+		{ui.SIZE_EXACT, ui.Const(1)},
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	}...)
 
 	grid := ui.NewGrid().Rows(rows).Columns([]ui.GridSpec{
-		{ui.SIZE_WEIGHT, 1},
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	})
 
 	switcher := &PartSwitcher{}
@@ -373,7 +373,7 @@ func (ps *PartSwitcher) MouseEvent(localX int, localY int, event tcell.Event) {
 			if localY < y && ps.parts[ps.selected].term != nil {
 				ps.parts[ps.selected].term.MouseEvent(localX, localY, event)
 			}
-			for i, _ := range ps.parts {
+			for i := range ps.parts {
 				if localY != y+i {
 					continue
 				}
@@ -511,11 +511,11 @@ func NewPartViewer(acct *AccountView, conf *config.AercConfig,
 	}
 
 	grid := ui.NewGrid().Rows([]ui.GridSpec{
-		{ui.SIZE_EXACT, 3}, // Message
-		{ui.SIZE_EXACT, 1}, // Selector
-		{ui.SIZE_WEIGHT, 1},
+		{ui.SIZE_EXACT, ui.Const(3)}, // Message
+		{ui.SIZE_EXACT, ui.Const(1)}, // Selector
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	}).Columns([]ui.GridSpec{
-		{ui.SIZE_WEIGHT, 1},
+		{ui.SIZE_WEIGHT, ui.Const(1)},
 	})
 
 	selecter := NewSelecter([]string{"Save message", "Pipe to command"}, 0).