feat: added the paged panel for easier making pagination stuff.

cmd/test/panel.go

@@ -5,45 +5,29 @@ import (
 )
 
 var DynamicPanelWidget = tg.RenderFunc(func(c tg.Context) tg.UI {
-	var (
-		n     = 0
-		ln    = 4
-		panel *tg.PanelCompo
-	)
-
-	panel = tg.Messagef(
-		"Some panel",
-	).Panel(c, tg.RowserFunc(func(c tg.Context) []tg.ButtonRow {
-		btns := []tg.ButtonRow{
-			tg.ButtonRow{tg.Buttonf("Page %d", n)},
-		}
-		for i := 0; i < ln; i++ {
-			num := 1 + n*ln + i
-			btns = append(btns, tg.ButtonRow{
-				tg.Buttonf("%d", num).Rand().WithAction(tg.Func(func(c tg.Context) {
-					_, err := c.Sendf("%d", num*num)
-					if err != nil {
-					}
-				})),
-				tg.Buttonf("%d", num*num),
-			})
-		}
-		btns = append(btns, tg.ButtonRow{
-			tg.Buttonf("Prev").WithAction(tg.Func(func(c tg.Context) {
-				n--
-				panel.Update(c)
-			})),
-			tg.Buttonf("Next").WithAction(tg.Func(func(c tg.Context) {
-				n++
-				panel.Update(c)
-			})),
-		})
-
-		return btns
-	}))
-
 	return tg.UI{
-		panel,
+		tg.Messagef("Paged panel").PagedPanel(
+			c, 0, 5,
+			func(c tg.Context, page, size int) tg.PanelPage {
+				rows := []tg.ButtonRow{}
+				for i := 0; i < size; i++ {
+					num := 1 + page*size + i
+					rows = append(rows, tg.ButtonRow{
+						tg.Buttonf("%d", num).Rand().WithAction(tg.Func(func(c tg.Context) {
+							_, err := c.Sendf("%d", num*num)
+							if err != nil {
+							}
+						})),
+						tg.Buttonf("%d", num*num),
+					})
+				}
+				return tg.PanelPage{
+					Rows: rows,
+					Next: page < 3,
+					Prev: page != 0,
+				}
+			},
+		),
 		tg.Messagef("").Reply(
 			BackKeyboard.Reply(),
 		),

paged-panel.go

@@ -0,0 +1,100 @@
+package tg
+
+type PanelPage struct {
+	Next, Prev bool
+	Rows []ButtonRow
+}
+
+type PanelPageFunc func(
+	c Context, page, size int,
+) PanelPage
+
+type PagedPanelCompo struct {
+	PanelCompo
+	page int
+	size int
+	nextFormat, prevFormat, delFormat string
+	fn PanelPageFunc
+}
+
+func (compo *MessageCompo) PagedPanel(
+	c Context,
+	startPage, size int,
+	fn PanelPageFunc,
+) (*PagedPanelCompo) {
+	ret := &PagedPanelCompo{}
+	ret.page = startPage
+	ret.size = size
+	ret.fn = fn
+	ret.prevFormat = "<<<"
+	ret.nextFormat = ">>>"
+	ret.delFormat = "..."
+
+	ret.PanelCompo = (*compo.Panel(
+		c, ret,
+	))
+
+	return ret
+}
+
+func (panel *PagedPanelCompo) MakeRows(
+	c Context,
+) []ButtonRow {
+	page := panel.fn(
+		c, panel.page, panel.size,
+	)
+
+	controlRow := ButtonRow{}
+
+	rows := page.Rows
+	next := func(c Context){
+		panel.page++
+		panel.Update(c)
+	}
+	prev := func(c Context){
+		panel.page--
+		panel.Update(c)
+	}
+
+	if page.Prev {
+		if panel.delFormat != "" {
+			rows = append(
+				[]ButtonRow{
+					ButtonRow{
+						Buttonf(panel.delFormat).Rand().
+							WithAction(Func(prev)),
+					},
+				},
+				rows...,
+			)
+		}
+		controlRow = append(
+			controlRow,
+			Buttonf(panel.prevFormat).Rand().
+				WithAction(Func(prev)),
+		)
+	}
+
+	if page.Next {
+		if panel.delFormat != "" {
+			rows = append(
+				rows,
+				ButtonRow{
+					Buttonf(panel.delFormat).Rand().
+						WithAction(Func(next)),
+				},
+			)
+		}
+		controlRow = append(
+			controlRow,
+			Buttonf(panel.nextFormat).Rand().
+				WithAction(Func(next)),
+		)
+	}
+
+	return append(
+		rows,
+		controlRow,
+	)
+}
+