Topics

#android #autocomplete #codeeditor #editor #large-text-editor #large-text-view #mtmanager #optimised #popup-window #selection-menu #smali #texteditor #theme #vscode-theme

Language breakdown

Java 78.8%

HTML 21.2%

▸ Files click to expand

README

📝 MH-TextEditor

A powerful, lightweight text editor for Android with syntax highlighting, smooth editing experience, and professional code editing features.

📱 Screenshots

| Screenshot 1 | Screenshot 2 | |------------------------------------------|------------------------------------------| | Screenshot 3 | Screenshot 4 | |------------------------------------------|------------------------------------------| | | Screenshot 6 |

✨ Features

🧩 Core Editing

Smooth Text Editing — Fast and responsive typing experience
Syntax Highlighting — Support for multiple programming languages (Java, XML, JSON, etc.)
Line Numbers — Clean, right-aligned line numbers with proper margins
Customizable Text Size — Pinch-to-zoom and manual text size adjustment
Multiple Font Support — Custom typeface support for better readability

✂️ Advanced Text Manipulation

Smart Selection — Word selection, line selection, and text range selection
Copy / Cut / Paste — Full clipboard support with system integration
Find & Replace — Regex-powered search and replace functionality
Undo / Redo — Unlimited undo/redo operations with gap buffer implementation
Auto-Indent — Smart indentation preservation on new lines

⚙️ Professional Tools

Magnifier — Built-in magnifier for precise cursor positioning
Selection Handles — Visual drag handles for text selection
Floating Clipboard Panel — Context-aware clipboard actions
Keyboard Support — Full hardware keyboard support with meta keys
Input Method Support — Optimized for various soft keyboards

⌨️ Computer Shortcuts

MH-TextEditor supports standard desktop-style keyboard shortcuts for productivity:

| Shortcut | Action | |----------|--------| | Ctrl + A | Select All | | Ctrl + C | Copy (Selection or Current Line) | | Ctrl + X | Cut (Selection or Current Line) | | Ctrl + V | Paste | | Ctrl + Z | Undo | | Ctrl + Y / Ctrl + Shift + Z | Redo | | Ctrl + D | Duplicate Current Line | | Ctrl + L | Select Current Line | | Ctrl + Shift + L | Delete Current Line | | Ctrl + / | Toggle Single-line Comment | | Ctrl + I | Increase Indent | | Ctrl + Shift + I | Decrease Indent | | Ctrl + U | Convert Selection to Lowercase | | Ctrl + Shift + U | Convert Selection to Uppercase | | Tab | Insert Tab / Indent Selection | | Shift + Tab | Decrease Indent | | Ctrl + Backspace | Delete Previous Word | | Ctrl + Delete | Delete Next Word | | Home / End | Move to Start / End of Line | | Ctrl + Home / End | Move to Start / End of File | | Ctrl + Left / Right | Move Cursor by Word | | Page Up / Down | Scroll Page Up / Down |

🚀 Performance & UX

Gap Buffer Implementation — Efficient text storage for large files 3M+ lines
Smooth Scrolling & zooming — Physics-based scrolling with fling gestures
Braces highlight - Efficently highlight close bracket , braces
Indent guidelines — Eficently render and handling guide lines
Cursor Blink — Visual cursor indication with customizable blink rate
Touch Gestures — Double-tap, long-press, and scroll gestures
Auto-complete — Intelligent word completion and suggestions

🚀 Getting Started

Basic Usage

<!-- In your layout XML -->
<modder.hub.editor.EditView
    android:id="@+id/editView"
    android:layoutwidth="matchparent"
    android:layoutheight="matchparent"
    android:focusableInTouchMode="true"/>

// In your Activity
EditView editView = findViewById(R.id.editView);
editView.setText("Your code here");
editView.setSyntaxLanguageFileName("java.json");

Advanced Configuration

// Set text size
editView.setTextSize(16); // in pixels
// Enable features editView.setMagnifierEnabled(true); editView.setAutoIndentEnabled(true);
// Set typeface Typeface typeface = Typeface.MONOSPACE; editView.setTypeface(typeface); editView.setMenuStyle(ClipboardPanel.MenuDisplayMode.ICON_ONLY); // Set listeners editView.addTextChangedListener(new TextWatcher() { 		@Override 		public void beforeTextChanged(CharSequence s, int start, int count, int after) { 			// Log.d(TAG, "beforeTextChanged: " + s.length()); 		}
@Override 		public void onTextChanged(CharSequence s, int start, int before, int count) { 			// Log.d(TAG, "onTextChanged: " + s.length()); 		}
@Override 		public void afterTextChanged(Editable s) { 			// Log.d(TAG, "afterTextChanged: " + s.length()); 		} 	});

🛠️ API Reference

Core Methods

| Method | Description | |--------|--------------| | setText(String text) | Set editor content | | getText() | Get current text | | setTextSize(float size) | Set text size in pixels | | setTypeface(Typeface typeface) | Set custom typeface | | setSyntaxHighlightingEnabled(boolean enabled) | Toggle syntax highlighting |

Editing Operations

| Method | Description | |--------|--------------| | undo() | Undo last operation | | redo() | Redo last operation | | copy() | Copy selected text | | cut() | Cut selected text | | paste() | Paste from clipboard | | selectAll() | Select all text | | clearSelection() | Clear current selection |

Navigation & Search

| Method | Description | |--------|--------------| | gotoLine(int line) | Navigate to specific line | | find(String regex) | Find text using regex | | replaceFirst(String replacement) | Replace first match | | replaceAll(String replacement) | Replace all matches |

Configuration

| Method | Description | |--------|--------------| | setEditedMode(boolean editMode) | Enable/disable editing | | setMagnifierEnabled(boolean enabled) | Toggle magnifier | | setAutoIndentEnabled(boolean enabled) | Toggle auto-indent | | setOnTextChangedListener(OnTextChangedListener listener) | Text change callback |

🎨 Customization

Theming

// Custom colors
editView.setBackgroundColor(Color.WHITE);
editView.setLineNumberBackground(Color.parseColor("#F8F8F8"));
editView.setLineNumberColor(Color.GRAY);

Syntax Highlighting

Add custom syntax definition files in JSON format to extend language support:

{
  "name": ["Java", ".java", ".jsp"],
  "comment": [
    { "startsWith": "//" },
    { "startsWith": "/", "endsWith": "/" }
  ],
"rules": [     // Single-line and multi-line comments     { "type": "comment", "regex": "//.*" },     { "type": "comment", "regex": "/\\[\\s\\S]?\\*/" },       // Triple-quoted strings     {       "regex": "\"\"\"[\\s\\S]*?\"\"\"",       "groupStyles": { "0": "string" }     },
// Quoted strings     { "type": "string", "regex": "\"(?:\\\\.|[^\"])*\"" },     { "type": "string", "regex": "'(?:\\\\.|[^'])'" }   ] }

📁 File Structure

app/
├── editor/
│   ├── EditView.java           # Main editor component
│   ├── GapBuffer.java          # Efficient text storage
│   ├── highlight/
│   │   └── SyntaxConfig.java   # Syntax highlighting engine
│   └── component/
│       └── ClipboardPanel.java # Clipboard context menu

🔄 Integration with Other Components

With Activity

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.editor_menu, menu);
    return true;
}
@Override public boolean onOptionsItemSelected(MenuItem item) {     switch (item.getItemId()) {         case R.id.menu_undo:             editView.undo();             return true;         case R.id.menu_redo:             editView.redo();             return true;         case R.id.menu_find:             showFindDialog();             return true;     }     return super.onOptionsItemSelected(item); }

With File System

// Load file
String fullText = readFile(path.toString());
// Replace buffer wholesale (like setText, but async)
GapBuffer newBuffer = new GapBuffer(fullText);
editView.setBuffer(newBuffer);
// Save file String content = editView.getText(); writeFile(filePath, content);

🐛 Troubleshooting

Common Issues

Keyboard not showing

- Ensure setFocusable(true) and setFocusableInTouchMode(true) are called - Check input connection implementation

Keyboard not supporting

- As of my test currently all keyboards are supporting without any issues

Syntax highlighting not working

- Verify syntax definition files are in assets - Check if highlighter is properly initialized

Performance with large files

- Use gap buffer optimization - Enable word wrap for better performance

Logging

Enable debug logging to troubleshoot issues:

Log.d("MH-TextEditor", "Current cursor: " + editView.getCaretPosition());

📄 License

Copyright (C) 2025 Krushna Chandra(@developer-krushna) This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <https://www.gnu.org/licenses/>.