assistassign.java

Python Development Environment (Python IDE plugin for Eclipse). Features editor, code completion, re

/*
 * Created on Apr 12, 2005
 *
 * @author Fabio Zadrozny
 */
package org.python.pydev.editor.correctionassist.heuristics;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.contentassist.ICompletionProposal;
import org.eclipse.swt.graphics.Image;
import org.python.pydev.codingstd.ICodingStd;
import org.python.pydev.core.IPythonNature;
import org.python.pydev.core.bundle.ImageCache;
import org.python.pydev.core.docutils.PySelection;
import org.python.pydev.core.docutils.StringUtils;
import org.python.pydev.editor.PyEdit;
import org.python.pydev.editor.actions.PyAction;
import org.python.pydev.editor.codecompletion.IPyCompletionProposal;
import org.python.pydev.plugin.PyCodeStylePreferencesPage;
import org.python.pydev.ui.UIConstants;

/**
 * @author Fabio Zadrozny
 */
public class AssistAssign implements IAssistProps {

    private ICodingStd std;

    public AssistAssign() {
        this(new ICodingStd(){

            public boolean localsAndAttrsCamelcase() {
                return PyCodeStylePreferencesPage.useLocalsAndAttrsCamelCase();
            }
            
        });
    }
    
    public AssistAssign(ICodingStd std) {
        this.std = std;
    }

    private Image getImage(ImageCache imageCache, String c){
        if(imageCache != null)
            return imageCache.get(c);
        return null;
    }
    
    /**
     * @see org.python.pydev.editor.correctionassist.heuristics.IAssistProps#getProps(org.python.pydev.core.docutils.PySelection, org.python.pydev.core.bundle.ImageCache, java.io.File, org.python.pydev.plugin.PythonNature)
     */
    public List<ICompletionProposal> getProps(PySelection ps, ImageCache imageCache, File f, IPythonNature nature, PyEdit edit, int offset) throws BadLocationException {
        List<ICompletionProposal> l = new ArrayList<ICompletionProposal>();
        String sel = PyAction.getLineWithoutComments(ps);
        if (sel.trim().length() == 0) {
            return l;
        }


        //go on and make the suggestion.
        //
        //if we have a method call, eg.:
        //  e.methodCall()| would result in the following suggestions:
        //
        //                   methodCall = e.methodCall()
        //					 self.methodCall = e.methodCall()
        //
        // NewClass()| would result in
        //
        //                   newClass = NewClass()
        //					 self.newClass = NewClass()
        //
        //now, if we don't have a method call, eg.:
        // 1+1| would result in
        //
        //					 |result| = 1+1
        //					 self.|result| = 1+1

        String callName = getTokToAssign(ps, sel);
        callName = changeToLowerUppercaseConstant(callName);

        if(callName.length() > 0){
            //all that just to change first char to lower case.
            if (callName.toLowerCase().startsWith("get") && callName.length() > 3){
                callName = callName.substring(3);
            }
            
            callName = changeToCodingStd(callName);
            
            for(int i=0;i<callName.length();i++){
                char c = callName.charAt(i);
                if(c != '_'){
                    callName = PyAction.lowerChar(callName, i);
                    break;
                }
            }
        }else{
            callName = "result";
        }
        
        String tok = callName;

        int firstCharPosition = PySelection.getFirstCharPosition(ps.getDoc(), ps.getAbsoluteCursorOffset());
        callName += " = ";
        l.add(new AssistAssignCompletionProposal(callName, firstCharPosition, 0, 0, getImage(imageCache, UIConstants.ASSIST_ASSIGN_TO_LOCAL),
                "Assign to local ("+tok+")", null, null, IPyCompletionProposal.PRIORITY_DEFAULT, edit));
        
        l.add(new AssistAssignCompletionProposal("self." + callName, firstCharPosition, 0, 5, getImage(imageCache,UIConstants.ASSIST_ASSIGN_TO_CLASS),
                "Assign to field (self."+tok+")", null, null, IPyCompletionProposal.PRIORITY_DEFAULT, edit));
        return l;
    }

    private String changeToLowerUppercaseConstant(String callName) {
        char[] cs = callName.toCharArray();
        for(char c: cs){
            if(Character.isLetterOrDigit(c) && !Character.isUpperCase(c)){
                return callName;
            }
        }
        return callName.toLowerCase();
    }

    private String changeToCodingStd(String callName) {
        if(!this.std.localsAndAttrsCamelcase()){
            StringBuffer ret = new StringBuffer();
            char[] cs = callName.toCharArray();
            
            boolean foundLower = false;
            
            for(char c: cs){
                if(Character.isUpperCase(c)){
                    if(foundLower){
                        ret.append('_');
                    }
                    foundLower = false;
                    ret.append(Character.toLowerCase(c));
                }else{
                    if(Character.isLowerCase(c)){
                        foundLower = true;
                    }
                    ret.append(c);
                }
            }
            return ret.toString();
        }else{
            return callName;
        }
    }

    /**
     * @see org.python.pydev.editor.correctionassist.heuristics.IAssistProps#isValid(org.python.pydev.core.docutils.PySelection, java.lang.String)
     */
    public boolean isValid(PySelection ps, String sel, PyEdit edit, int offset) {
        try {
            if(! (ps.getTextSelection().getLength() == 0))
                return false;

            String lineToCursor = ps.getLineContentsToCursor();

            if( ! ( sel.indexOf("class ") == -1 && sel.indexOf("def ") == -1 && sel.indexOf("import ") == -1))
                return false;

            String eqReplaced = sel.replaceAll("==", "");
            if (eqReplaced.indexOf("=") != -1){ //we have some equal
                //ok, make analysis taking into account the first parentesis
                if(eqReplaced.indexOf('(') == -1){
                    return false;
                }
                int i = eqReplaced.indexOf('(');
                if(eqReplaced.substring(0, i).indexOf('=') != -1){
                    return false;
                }
            }
            
            if( lineToCursor.trim().endsWith(")"))
                return true;
            
            if( lineToCursor.indexOf('.') != -1)
                return true;
            
            
        } catch (BadLocationException e) {
            return false;
        }
        return true;
    }

    /**
     * @param ps
     * @return
     */ 
    private String getTokToAssign(PySelection ps, String sel) {
        String beforeParentesisTok = PyAction.getBeforeParentesisTok(ps);
        if(beforeParentesisTok.length() > 0){
            return beforeParentesisTok;
        }
        //otherwise, try to find . (ignore code after #)
        String string = PyAction.getLineWithoutComments(ps);
        String callName = "";
        //get parentesis position and go backwards
    
        int i;
        if ((i = string.lastIndexOf(".")) != -1) {
            callName = "";
    
            for (int j = i+1; j < string.length() && PyAction.stillInTok(string, j); j++) {
                callName += string.charAt(j);
            }
        }
        if(callName.length() == 0){
            if(StringUtils.isSingleWord(sel.trim())){
                return sel.trim();
            }
        }
        return callName;
    }

}