CODEWITHSUNDEEP
androidkotlinanko
Marvin
Marvin

Reputation: 1855

How to reference other views in Anko DSL?

I'm using Anko in my Android project, but I don't know how can it reference the child views I created in the DSL when the referenced view is not at the same level where I reference it.

The following code works:

alert {
    customView {
        val input = textInputLayout {
            editText {
                hint = "Name"
                textColor =resources.getColor(R.color.highlight)
            }
        }


        positiveButton("OK") { "${input.editText.text}" }
    }
}.show()

but the following code does not work:

alert {
    customView {
        val vertical = verticalLayout {
            textView {
                text = "Edit device name"
                textColor = resources.getColor(R.color.highlight)
                textSize = 24F
            }
            val input = textInputLayout {
                editText {
                    hint = "Name"
                    textColor = resources.getColor(R.color.highlight)
                }
            }
        }

        positiveButton("OK") { "${vertical.input.editText.text}" }  // Cannot resolve "input"
    }
}.show()

Upvotes: 15

Views: 3200

Answers (5)

Antek
Antek

Reputation: 739

I usually declare a view as a property in a class with lateinit modifier; this way it's not nullable and most of views are declared in one place, improving readability:

lateinit var toolbar: Toolbar

...
appBarLayout {
    toolbar = toolbar {}.lparams(width = matchParent, height = matchParent)
             }.lparams(width = matchParent)
...
setSupportActionBar(toolbar)

Upvotes: 1

Shayne Fitzgerald
Shayne Fitzgerald

Reputation: 101

Probably the best way is to use Android IDs for the elements you need to reference later, and the find<T : View>(Int) : T function. This allows you to reference them from anywhere, as long as the view still exists, and you have access to the application/activity scope.

See the Anko Documentation for details

Example case: Dynamically adding buttons to an existing view

verticalLayout {
  id = R.id.button_container
}
//note that the code below here may be executed anywhere after the above in your onCreate function
//verticalLayout is a Anko subclass of LinearLayout, so using the android class is valid.
val buttonContainer = find<LinearLayout>(R.id.button_container)

val containerContext = AnkoContext.Companion.create(ctx, buttonContainer)
val button = ctx.button {
  text = "click me"
  onClick = { toast("created with IDs!") }
}
buttonContainer.addView(button.createView(containerContext, buttonContainer))

Upvotes: 0

voddan
voddan

Reputation: 33749

You can always elevate a view, passing the context vertical manually:

customView {
    val vertical = verticalLayout {
        textView {
            text = "Edit device name"
            textColor = resources.getColor(R.color.highlight)
            textSize = 24F
        }
    }

    val input = /*here:*/ vertical.textInputLayout {
        editText {
            hint = "Name"
            textColor = resources.getColor(R.color.highlight)
        }
    }

    positiveButton("OK") { "${input.editText.text}" }
}

Upvotes: 1

Nevin Chen
Nevin Chen

Reputation: 1815

I propose using findViewById()

alert {
        customView {
            val vertical = verticalLayout {
                textView {
                    text = "Edit device name"
                    textSize = 24F
                }
                val input = textInputLayout {
                    editText {
                        id = R.id.my_id_resource // put your id here
                        hint = "Name"
                    }
                }
            }
            positiveButton("OK") { "${(vertical.findViewById(R.id.my_id_resource) as? EditText)?.text}" }  
        }
    }.show()

Upvotes: 2

Kirill Rakhman
Kirill Rakhman

Reputation: 43811

As I see it there are two ways. The super hacky way would be to declare the positive button within the textInputLayout block. This is possible because you can access all outer scopes from within any nested scope and the positiveButton method is declared in the alert scope:

alert {
    customView {
        verticalLayout {
            textInputLayout {
                val editText = editText {
                    hint = "Name"
                }

                positiveButton("OK") { toast("${editText.text}") }
            }
        }
    }
}.show()

The less hacky way would be to declare a variable that can be accessed from both scopes. However you would need to make it nullable since you can't initialize it immediately:

alert {
    var editText: EditText? = null

    customView {
        verticalLayout {
            textInputLayout {
                editText = editText {
                    hint = "Name"
                }
            }
        }
    }

    positiveButton("OK") { toast("${editText!!.text}") } 
}.show()

Upvotes: 6

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