使用GXUI在Go中滚动窗口

Question

I am trying to add scroll bars to my application windows in Go using GXUI.

Say I have this code:

package main

import (
    "fmt"

    "github.com/google/gxui"
    "github.com/google/gxui/drivers/gl"
    "github.com/google/gxui/samples/flags"
    "github.com/google/gxui/themes/dark"
)

func appMain(driver gxui.Driver) {
    theme := dark.CreateTheme(driver)

    window := theme.CreateWindow(800, 600, "Grid")
    window.SetScale(flags.DefaultScaleFactor)
    window.OnClose(driver.Terminate)

    row := theme.CreateLinearLayout()
    row.SetDirection(gxui.LeftToRight)
    for c := 0; c < 4; c++ {
        col := theme.CreateLinearLayout()
        col.SetDirection(gxui.TopToBottom)
        for r := 0; r < 100; r++ {
            cell := theme.CreateLabel()
            cell.SetText(fmt.Sprintf("%d", r*4+c))
            col.AddChild(cell)
        }
        row.AddChild(col)
    }

    window.AddChild(row)
}

func main() {
    gl.StartDriver(appMain)
}

When I run it, I get this window:

How can I get the window to have a scroll bar so that I can view all of the lines?

Answer 1

The following code uses ScrollLayout to add a scroll bar to the window. The trick is to make ScrollLayout the window's child and make the next widget (in this case a LinearLayout) a child of the ScrollLayout.

package main

import (
    "fmt"
    "github.com/google/gxui"
    "github.com/google/gxui/drivers/gl"
    "github.com/google/gxui/samples/flags"
    "github.com/google/gxui/themes/dark"
)

func appMain(driver gxui.Driver) {
    theme := dark.CreateTheme(driver)
    window := theme.CreateWindow(800, 600, "Grid")
    window.SetScale(flags.DefaultScaleFactor)
    window.OnClose(driver.Terminate)
    sl := theme.CreateScrollLayout()
    row := theme.CreateLinearLayout()
    row.SetDirection(gxui.LeftToRight)
    for c := 0; c < 4; c++ {
        col := theme.CreateLinearLayout()
        col.SetDirection(gxui.TopToBottom)
        for r := 0; r < 100; r++ {
            cell := theme.CreateLabel()
            cell.SetText(fmt.Sprintf("%d", r*4+c))
            col.AddChild(cell)
        }
        row.AddChild(col)
    }
    sl.SetChild(row)
    window.AddChild(sl)
}

func main() {
    gl.StartDriver(appMain)
}

Note that my computer gave me display issues when I increased the number of rows (the rightmost columns began to get cut off), but other people did not encounter this issue, so it is likely due to a bad installation on my end.