Highlight

A complete and performing library to highlight text snippets (EditText/Editable and TextView) using Spannable with Regular Expressions (Regex) for Android.

Highlight a text

To highlight a text, just create an instance of Highlight, add the Schemes and use setSpan() method to add to a TextView or EditText.

//create an instance of Highlight
Highlight highlight = new Highlight();

//add Schemes
highlight.addScheme(
        new ColorScheme(
                Pattern.compile("\\b([Jj])ava\\b"),
                Color.parseColor("#FC0400")
        ),
        new ColorScheme(
                Pattern.compile("\\b([Kk])otlin\\b"),
                Color.parseColor("#FC8500")
        )
);

//highlight the text
highlight.setSpan(binding.edittext);
highlight.setSpan(binding.textview);

Continuously highlight

To continuously highlight an EditText whenever it is edited, create an instance of HighlightTextWatcher, add the Schemes and add the listener to the EditText.

//create an instance of HighlightTextWatcher
HighlightTextWatcher highlightTextWatcher = new HighlightTextWatcher();

//add schemes
highlightTextWatcher.addScheme(
        new StyleScheme(
                Pattern.compile("\\b([Jj])ava\\b"),
                StyleScheme.STYLE.BOLD_ITALIC
        ).setClearOldSpan(true),
        new StyleScheme(
                Pattern.compile("\\b([Kk])otlin\\b"),
                StyleScheme.STYLE.BOLD_ITALIC
        ).setClearOldSpan(true)
);

//add the listener
binding.edittext.addTextChangedListener(highlightTextWatcher);

Schemes

Use the default schemes; ColorScheme, OnBackgroundScheme, StyleScheme, FontScheme, LinkScheme and OnClickScheme, or implement the Scheme interface to create a custom scheme.

...

highlight.addScheme(
        new StyleScheme(
                Pattern.compile("Highlight"),
                StyleScheme.STYLE.BOLD_ITALIC
        ).addScopeScheme(
                //scheme in scope of other schemes
                new ColorScheme(
                        Pattern.compile("light"),
                        Color.parseColor("#FF03DAC5")
                )
        )
);

highlight.addScheme(
        //clickable links
        new LinkScheme().setPainTextUnderline(false)
);

highlight.addScheme(
        //clickable text
        new OnClickScheme(
                Pattern.compile("Highlight"),
                new OnClickScheme.OnClickListener() {
                    @Override
                    public void onClick(CharSequence text) {
                        goToURL("https://github.com/Irineu333/Highlight");
                    }
                }
        )
);

highlight.addScheme(
        new ColorScheme(
                Pattern.compile("Project"),
                Color.BLACK
        ).addScopeScheme(
                //font scheme
                new FontScheme(
                        FontScheme.getFont(this, R.font.pacifico_regular)
                )
        )
);

...

SchemeScope

Every schema has a scope to which other schemas can be added via the addScopeScheme (...) method. Schemes added to a scope will run only within that scope, saving processing and creating possibilities for smarter highlights.

Highlight highlight = new Highlight();

highlight.addScheme(
        new StyleScheme(
                Pattern.compile("Highlight"),
                StyleScheme.STYLE.BOLD_ITALIC
        ).addScopeScheme(
                //add scheme scope in any scheme
                new ColorScheme(
                        Pattern.compile("light"),
                        Color.parseColor("#FF03DAC5")
                )
        )
);

highlight.addScheme(
        //use scope to group schemes
        new Scope(Pattern.compile("Project"),
                new ColorScheme(Color.BLACK),
                new FontScheme(FontScheme.getFont(this, R.font.pacifico_regular))
        )
);

highlight.setSpan(binding.toolbarTitle);

Performance

This lib was born out of a solution. One of the problems you will face if you try to create a syntax highlighting is the bottleneck for editing very large code. This lib was born from a simple but ingenious solution (in my opinion) that I arrived together with some friends, which is the processing by altered lines. Basically, when activated (in by default it is), this lib will only process the lines that undergo some change, no matter how many.

Screenshots

Simple Highlighting	Kotlin Highlighting	Kotlin Highlighting

Kotlin

In projects that support Kotlin, use the version optimized for Kotlin, Highlight-KT.

Add to project

Add the jitpack to project in build.gradle or settings.gradle (gradle 7+)

maven { url 'https://jitpack.io' }

Add the dependence to module (normally app)

implementation "com.github.Irineu333:Highlight:$highlight_version"