LANCARD.LAB｜ランカードコムのスタッフブログ

package com.lancard.editor.action;
 
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.ITextSelection;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.ui.IEditorActionDelegate;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.texteditor.IDocumentProvider;
import org.eclipse.ui.texteditor.ITextEditor;
 
public class FormatAction implements IEditorActionDelegate {
	private IEditorPart targetEditor = null;
	public void run(IAction action) {
		ITextEditor textEditor = (ITextEditor)targetEditor;
		ISelectionProvider selectionProvider = textEditor.getSelectionProvider();
		ISelection selection = selectionProvider.getSelection();
		ITextSelection textSelection = (ITextSelection)selection;
		textSelection.getStartLine();
		try{
			execute(textSelection.getStartLine(),textSelection.getEndLine());
		}catch(BadLocationException e){
			//ログとか出したほうがいい。
		}
	}
	private void execute(int startLine,int endLine) throws BadLocationException {
		ITextEditor textEditor = (ITextEditor)targetEditor;
		IDocumentProvider provider = textEditor.getDocumentProvider();
		IDocument document = provider.getDocument(textEditor.getEditorInput());
		int maxIndex = 0;
		for(int line=startLine;line<=endLine;line++){
			int length = document.getLineLength(line);
			int offset = document.getLineOffset(line);
			String value = document.get(offset, length);
			int equalsIndex = value.indexOf("=");
			if(equalsIndex<0){
				continue;
			}
			if(equalsIndex>maxIndex){
				maxIndex = equalsIndex;
			}
		}
 
		for(int line=startLine;line<=endLine;line++){
			int length = document.getLineLength(line);
			int offset = document.getLineOffset(line);
			String value = document.get(offset, length);
			int equalsIndex = value.indexOf("=");
			if(equalsIndex<0){
				continue;
			}
			if(equalsIndex<maxIndex){
				document.replace(offset, length, newValue(value, equalsIndex, maxIndex));
			}
		}
	}
	private String newValue(String value,int equalsIndex,int maxIndex){
		StringBuilder sb = new StringBuilder();
		String prev = value.substring(0,equalsIndex);
		String next = value.substring(equalsIndex);
		sb.append(prev);
		for(int i=equalsIndex;i<maxIndex;i++){
			sb.append(" ");
		}
		sb.append(next);
		return sb.toString();
	}
	public void selectionChanged(IAction action, ISelection selection) {
	}
 
	public void setActiveEditor(IAction action, IEditorPart targetEditor) {
		this.targetEditor = targetEditor;
	}
}