UI Resources

(A) Layout Resources

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(B) UI Elements

(a) Views & ViewGroup

Views

• • Views are the fundamental building blocks used to create an app’s user interface (UI).
  • Each view represents a visual component that the user can interact with or display information.
  • Views are the fundamental building block/object of the user interface created from the View class.
  • Views is a small/large rectangular area on the screen and is responsible for drawing and event handling in the Android app.
  • View is the base class for widgets, which are used to create interactive UI components like buttons, text fields, etc.
  • Views in Android can be arranged and customized using XML layout files or programmatically through Java or Kotlin code.
  • Some common View elements used in Android applications are:-
    • Basic Views:
      • TextView:
        • TextView is a basic UI widget that displays text to the user.
        • It is one of the most fundamental building blocks for displaying static or dynamic text in Android apps.
        • We can customize its appearance and behavior using various XML attributes.
        • It is a simple text display element.
        • This view displays text on the screen and can be used to show static or dynamically changing text content.
        • It acts as a label.
      • Plain Text
        • In Android, the PlainText widget is used to provide a simple text input field where users can enter single-line text, such as usernames, search queries, or other text inputs.
        • In the Android SDK, this widget is called EditText, but when we see PlainText in the Palette of Android Studio’s Layout Editor, it’s essentially a pre-configured EditText for single-line input.
        • We can customize the behavior of the PlainText field by using different input type values depending on the kind of data we want the user to input.
          • For Single-line text (default): android:inputType=”text”
          • For Email: android:inputType=”textEmailAddress”
          • For Password: android:inputType=”textPassword”
          • For Phone/Mobile number: android:inputType=”phone”
          • For Numeric Value: android:inputType=”number”
        • This view is almost similar to EditText.
      • EditText:
        • It is a user-input text box/field.
        • It’s used for accepting user input such as text, numbers, etc.
      • Password:
        • In Android, the Password input field is created using the EditText widget with a specific inputType that masks the characters as they are typed.
        • The EditText widget allows for secure entry of passwords by displaying dots or asterisks instead of the actual characters. This is done by setting the android:inputType attribute to “textPassword” or “numberPassword”.
        • Android provides a convenient way to toggle the visibility of the password. This can be done using the android:passwordToggleEnabled=”True” feature in conjunction with TextInputLayout. It allows users to see the password when they click an eye icon next to the field.
        • To Limit the number of characters a user can enter for the password using android:maxLength=”30″ .
        • If we want to show error messages when the password is incorrect, we can do so using textInputLayout.setError(“Password must be at least 6 characters long.”);.
      • Button:
        • This view is used to represent a clickable button that triggers an action/event when pressed by the user.
      • ImageView:
        • It is used to display images or drawables on the screen.
    • Container Views:
      • ScrollView:
        • It allows scrolling of the contents if they exceed the screen size.
      • ListView:
        • It displays a scrollable list of items.
      • RecyclerView:
        • It is a more advanced and efficient list view that efficiently displays large sets of data by recycling views.
      • ViewPager:
        • It enables the user to swipe left or right to view different content screens.
      • TabLayout:
        • It represents tabs for switching between different views or sections within an app.
      • Navigation Drawer:
        • It is a sliding panel that displays app navigation options.
    • Interactive Views:
      • CheckBox:
        • It is used to represent a box that can be checked or unchecked by the user.
        • This view is used as multi-select or zero-select options at a time.
      • RadioButton:
        • This view is used to present a set of options where only one can be selected at a time.
      • SeekBar:
        • It is used to display a draggable bar allowing the user to select a value from a range.
    • Specialized Views:
      • DatePicker and TimePicker:
        • It allows users to select dates and times respectively.
      • WebView:
        • It displays web content within the app, allowing for the integration of web-based features.
      • Spinner:
        • It represents a dropdown list allowing users to select one item from multiple options.
      • SeekBar:
        • It provides a draggable thumb to select a value from a range, often used for adjusting settings like volume or brightness.
      • ProgressBar:
        • It indicates the progress of an operation or task that is going on or completed.

ViewGroup

• • The ViewGroup is a subclass of View and provides an invisible container that holds other Views or other ViewGroups and defines their layout properties.

(b) Intent

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(c) Toast

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