Home > Java > javaTutorial > body text

How to Paginate Text within a TextView Control in Android?

Barbara Streisand
Release: 2024-11-09 18:26:02
Original
967 people have browsed it

How to Paginate Text within a TextView Control in Android?

Paginating Text in Android

Problem:

Paginating text within a TextView control in Android requires determining when and how to break the text into pages. This can be challenging as TextView's line-breaking and page-breaking algorithms are not readily accessible, making it difficult to identify where the text ends on the actual display.

Solution:

By monitoring the visible text range using the ViewTreeObserver, it is possible to track the last line that fully fits within the view's height. This allows for the creation of pages based on the cumulative height of the lines, ensuring that pages are broken when a line is encountered that exceeds the available vertical space.

Algorithm:

  1. Iterate through the lines of text and check if the line's bottom exceeds the view's height.
  2. If so, break a new page and calculate a new cumulative height value based on the top of the last line that did not fit on the previous page plus the view's height.

Implementation:

To implement this algorithm, use the following code:

// Setup code
ViewTreeObserver vto = txtViewEx.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {
        ViewTreeObserver obs = txtViewEx.getViewTreeObserver();
        obs.removeOnGlobalLayoutListener(this);
        height = txtViewEx.getHeight();
        scrollY = txtViewEx.getScrollY();
        Layout layout = txtViewEx.getLayout();
        firstVisibleLineNumber = layout.getLineForVertical(scrollY);
        lastVisibleLineNumber = layout.getLineForVertical(height + scrollY);
    }
});
Copy after login

Note:

This solution efficiently paginates text while respecting line height and character spacing. It also handles special characters and dynamic text changes.

The above is the detailed content of How to Paginate Text within a TextView Control in Android?. For more information, please follow other related articles on the PHP Chinese website!

source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Latest Articles by Author
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template