How to create dynamic screens at runtime that were not pre-designed?

Dynamic screens at runtime can be implemented using the following approaches:

1. XML Layout Inflation: The most common method. You can create standard or parameterized XML layout files and dynamically load them at runtime using LayoutInflater. This allows changing the screen structure based on data or application logic.

   // Get LayoutInflater
   val layoutInflater = LayoutInflater.from(context)
   
   // Inflate layout
   val dynamicView = layoutInflater.inflate(R.layout.dynamic_layout, parentViewGroup, false)
   
   // Add view to parent container
   parentViewGroup.addView(dynamicView)
   

2. Programmatic View Creation: Creating views and defining their properties (position, size, margins, etc.) entirely programmatically. This approach offers maximum flexibility but can be more cumbersome for complex layouts.

   // Create TextView programmatically
   val textView = TextView(context)
   
   // Set text
   textView.text = "Dynamic Text"
   
   // Set layout parameters (e.g., for LinearLayout)
   val layoutParams = LinearLayout.LayoutParams(
       LinearLayout.LayoutParams.WRAP_CONTENT,
       LinearLayout.LayoutParams.WRAP_CONTENT
   )
   layoutParams.topMargin = 16.dpToPx(context) // Example of setting top margin
   
   // Apply layout parameters
   textView.layoutParams = layoutParams
   
   // Add view to parent container
   parentViewGroup.addView(textView)
   

3. Data-Driven UI: Using data (e.g., from API or local database) to determine the structure and content of the screen. This can be implemented by parsing configuration data (e.g., JSON) and dynamically building the UI based on this information using approaches 1 or 2.

   Example JSON structure for configuration:

   {
     "screen": {
       "type": "LinearLayout",
       "orientation": "vertical",
       "children": [
         {
           "type": "TextView",
           "text": "Hello, world!",
           "textSize": 18
         },
         {
           "type": "Button",
           "text": "Press me",
           "action": "showToast"
         }
       ]
     }
   }
   

   Parsing this JSON and programmatically creating the corresponding views.

4. Templating: Creating a set of standard "templates" or "building blocks" (components) that can be combined and configured at runtime based on input data. This is a combination of approaches 1 and 3. You can have predefined XML fragments that are inflated and filled with data dynamically.

5. Using libraries for dynamic UI: There are third-party libraries that provide higher-level abstractions for creating dynamic screens based on data.

The choice of approach depends on the complexity of the required dynamic capabilities and the level of flexibility. Usually, a combination of XML layout inflation and data-driven UI is the most balanced solution for typical tasks.