Adding More UITextField on View When Typing On A UITextField

Introduction

In this article, we will explore how to dynamically add more UITextFields to a view when typing occurs in the first one. We’ll break down the solution into manageable steps and cover the necessary concepts and code snippets.

Problem Statement

We want to create multiple UITextFields on a view depending on the condition. When typing begins in the first UITextField, another one should be created at the bottom, and when typing starts on the second one, the third one will be added below it. Conversely, if there is no text in the top UITextField, we want to delete the bottom text field.

Overview

Our approach involves:

1. Creating a global variable (tagCounter) to keep track of the number of UITextFields created.
2. Setting up the first UITextField with its delegate and tag counter value.
3. Implementing methods for creating new UITextFields and removing existing ones based on user input.
4. Using the textFieldDidEndEditing: method to trigger these operations.

Step 1: Global Variable Declaration

First, let’s declare a global variable (tagCounter) to manage our UITextField count:

int tagCounter = 1;

This counter will help us identify and remove existing text fields when new ones are created or when no input is detected in the top field.

Step 2: Setting Up First UITextField

To set up the first UITextField, we need to:

• Set its delegate to our class (self):

[MyFirstTextField setDelegate:self];

*   Assign a unique tag counter value (starting from 1) to the field:
    ```markdown
[MyFirstTextField setTag:tagCounter];
tagCounter += 1;

This step establishes a connection between our class and the first UITextField, allowing us to track its state and receive notifications when it ends editing.

Step 3: Creating New UITextField

When we want to create a new UITextField below an existing one, we’ll use the following method:

-(void)CreateNewTextField:(float)FromTop withTag:(int)Tag {
    // Create a new text field
    UITextField *newTextField = [[UITextField alloc] initWithFrame:CGRectMake(0.0f, FromTop, 100.0f, 40.0f)];
    
    // Set the delegate to our class
    [newTextField setDelegate:self];
    
    // Assign a unique tag counter value to the new field
    [newTextField setTag:Tag];
    
    // Add the new text field to our view
    [[self view] addSubview:newTextField];
}

This method takes two parameters:

• FromTop: The y-coordinate where we want to position the new UITextField, calculated as the top edge of the current one plus its height.
• Tag: The unique identifier assigned to this new field, used for removal purposes.

By calling this method when the user starts typing on an existing UITextField, a new one will be created below it with a different tag value.

Step 4: Removing Existing UITextField

To remove an existing UITextField based on its tag, we can use the following method:

-(void)RemoveTextField:(int)Tag {
    // Iterate through all subviews to find the text field to remove
    for (UIView *subView in [[self view] subviews]) {
        if ([subView isKindOfClass:[UITextField class]]) {
            if ([subView tag] >= Tag) {
                // Remove the text field from our view hierarchy
                [subView removeFromSuperview];
            }
        }
    }
}

This method takes a single parameter: Tag, which represents the unique identifier of the UITextField to remove.

When called when no input is detected in the top UITextField, this method will find and delete the corresponding text field from our view hierarchy, thus maintaining an optimal number of visible fields.

Step 5: Using textFieldDidEndEditing:

To connect these operations, we’ll use the textFieldDidEndEditing: method:

-(void)textFieldDidEndEditing:(UITextField *)textField {
    if ([[[textField text] isEqualToString:@""]] {
        int currentTag = [textField tag];
        // Remove the previous text field when no input is detected in the top one
        [self RemoveTextField:currentTag + 1];
    } else {
        CGRect currentTextFieldFrame = textField.frame;
        // Create a new text field below the current one with a different tag value
        [self CreateNewTextField:currentTextFieldFrame.origin.y + currentTextFieldFrame.size.height + 20.0f withTag:tagCounter];
        tagCounter += 1;
    }
}

This method is triggered when the user finishes editing the UITextField. If no input was entered, it removes the previous text field using its tag value. Otherwise, it creates a new one below it with an updated tag value.

Conclusion

In this article, we have discussed how to create multiple UITextFields on a view dynamically based on user input and remove existing fields when necessary. By implementing these methods and connecting them through the textFieldDidEndEditing: event handler, we can efficiently manage our text field count while maintaining an optimal number of visible fields.

Additional Considerations

• Make sure to adjust your layout accordingly to accommodate multiple UITextFields.
• Be mindful of your user’s expectations when creating or removing fields dynamically.
• For more complex scenarios, you may want to explore additional UI elements, such as buttons or labels.

Last modified on 2023-08-01