io Programmo 14/IOPROG_14.ISO/soft/sdkjava/sdkjava.exe/SDKJava.cab/Samples/AFC/JNotepad/src/DiskFileControl.java

Java Source | 1998-03-05 | 7.7 KB | 348 lines

//
// (c) 1998 Microsoft Corporation.  All rights reserved.
//

import FileControl;
import java.io.*;
import java.awt.Frame;
import com.ms.ui.*;
import java.util.StringTokenizer;

/**
*    Implementation of abstract class FileControl for disk files. Encapsulates a
*    file and handles file loading/saving/etc into an edit control.
*
*    @see     FileControl
*
*    @version    1.0, 7/15/97
*/

public class DiskFileControl extends FileControl
{
    /**
    *    Whether the file separates lines with CRLFs or CRs.
    */
    protected boolean bIsCRLF;

    /**
     * Creates a new DiskFileControl.
     *
     *    @param    toTarget    Edit control which this file will display in
     *    @param    parentFrame    Parent frame window.
     */
    public DiskFileControl(ITextOperationTargetExt toTarget, UIFrame parentFrame)
    {
        super(toTarget, parentFrame);
        bIsCRLF=true;
    }

    /**
     *    Creates a new file in the edit control. Part of IFileOperationTarget.
     */
    public void newFile()
    {
        editControl.setText("");
        setFile(null,null);
    }

    // assumes that the new file name has already been set
    // via setFileName()
    /**
     *    Saves the file to disk under a different
     *    name. Assumes that the new filename has been set using setFileName(). Part of IFileOperationTarget.
     */
    public boolean saveFileAs()
    {
        return saveFile();
    }

    /**
     *    Saves the file to disk under the current
     *    name. Simply writes the contents of the edit control to disk. Part of IFileOperationTarget.
     */
    public boolean saveFile()
    {
        if (isReadOnly())
        {
            // file cannot be written to
            UIMessageBox box = new UIMessageBox(new UIFrame(),
                JNotePad.loadString(ResourceIDs.IDS_MSGTITLE),
                JNotePad.loadString(ResourceIDs.IDS_MSGREADONLY),
                box.STOP, UIButtonBar.OK);
            box.doModal();
            return false;
        }

        DataOutputStream file = null;

        // display a wait cursor while we're waiting
        int iOldCursor = showWaitCursor();

        try
        {
            file = new DataOutputStream(new FileOutputStream(getFileLocation()));
        }
        catch (IOException e)
        {
            // file save problem
            UIMessageBox box = new UIMessageBox(new UIFrame(),
                JNotePad.loadString(ResourceIDs.IDS_MSGTITLE),
                JNotePad.loadString(ResourceIDs.IDS_MSGNOSAVE),
                box.STOP, UIButtonBar.OK);
            box.doModal();

            // restore old cursor
            setCursor(iOldCursor);

            return false;
        }

        boolean ret = true;

        // characters which mark end of line. If bIsCRLF is true, then append
        // a carriage return-line feed pair, otherwise just use a carriage return
        String lineTerminator = (bIsCRLF ? "\r\n" : "\r");

        try
        {
            String line = editControl.getText();
            //file.writeBytes(line);

            //line.replace('\n', '\r');
            int iIndex = line.indexOf('\n');
            int iOldIndex = 0;
            while (iIndex > -1)
            {
                file.writeBytes(line.substring(iOldIndex, iIndex));

                file.writeBytes(lineTerminator);

                iOldIndex = iIndex+1;
                iIndex = line.indexOf('\n', iOldIndex);
            }
            //file.writeBytes("\n");
        }
        catch (IOException e)
        {
            // can't write to disk
            UIMessageBox box = new UIMessageBox(new UIFrame(),
                JNotePad.loadString(ResourceIDs.IDS_MSGTITLE),
                JNotePad.loadString(ResourceIDs.IDS_MSGNOSAVE),
                box.STOP, UIButtonBar.OK);
            box.doModal();

            ret = false;
        }

        try
        {
            file.close();
        }
        catch (IOException e1)
        {
        }

        // newly saved files are clean (not dirty)
        setDirtyFlag(false);

        // restore the old cursor
        setCursor(iOldCursor);

        return ret;
    }

    /**
    *    Checks if the file uses CRLF to separate lines or CRs only.
    *    Returns the next string in the file and sets the bIsCRLF member variable. Note that
    *    this string has a carriage return appended to it.
    */
    private String checkIfCRLF(DataInputStream file)
    {
        StringBuffer buffer = new StringBuffer(85);
        byte[] b = new byte[1];
        boolean bHitCR = false;

        bIsCRLF = false;

        try
        {
            // read file until CR hit. Set a flag and stop reading when that happens.
            int iNumRead = 0;
            b[0] = 0;
            while (iNumRead > -1)
            {
                iNumRead = file.read(b);

                if (b[0] == '\r')
                {
                    bHitCR = true;
                    iNumRead = -2;
                }
                else
                {
                    buffer.append((char)b[0]);
                }
            }

            // if we've hit a CR
            if (bHitCR == true)
            {
                // read next char. If this fails, b[0] will be unchanged, which is fine.
                // we only want to do something special if b[0] is \n (i.e. the next char
                // is LF) and if this hits EOF, b[0] will remain what it was.
                file.read(b);

                // append a carriage return
                buffer.append('\n');
                if (b[0] == '\n')
                {
                    // CR followed by a LF. Clearly we're using CRLFs in this file.
                    bIsCRLF = true;
                }
                else
                {
                    // not using CRLF in this class. Append the character we read.
                    bIsCRLF = false;
                    buffer.append((char)b[0]);
                }
            }

        }
        catch (IOException e)
        {
            return null; // !!
        }

        return buffer.toString();

    }

    /**
    *    Opens a file from disk and loads it into
    *    the edit control. Assumes filename has already been set by setFileName(). Part of IFileOperationTarget.
    */
    public boolean openFile()
    {
        DataInputStream file = null;

        try
        {
            file = new DataInputStream(new FileInputStream(getFileLocation()));
        }
        catch (IOException e)
        {
            // file not found
            UIMessageBox box = new UIMessageBox(new UIFrame(),
                JNotePad.loadString(ResourceIDs.IDS_MSGTITLE),
                JNotePad.loadString(ResourceIDs.IDS_MSGFILENOTFOUND)+getFileLocation(),
                box.STOP, UIButtonBar.OK);
            box.doModal();

            return false;
        }

        // display a wait cursor while we're waiting
        int iOldCursor = showWaitCursor();

        boolean ret = true;

        // check if we should read files with CR or CRLF at end of the lines.
        String line = checkIfCRLF(file);
        editControl.setText("");
        editControl.appendText(line);

        try
        {
            line = file.readLine();

            while (line != null)
            {
                editControl.appendText(line+"\n");
                line = file.readLine();
            }

        }
        catch (IOException e)
        {
            // file read error
            UIMessageBox box = new UIMessageBox(new UIFrame(),
                JNotePad.loadString(ResourceIDs.IDS_MSGTITLE),
                JNotePad.loadString(ResourceIDs.IDS_MSGFILEREAD),
                box.STOP, UIButtonBar.OK);
            box.doModal();

            ret = false;
        }

        try
        {
            file.close();
        }
        catch (IOException e1)
        {
            // internal saving error
            UIMessageBox box = new UIMessageBox(new UIFrame(),
                JNotePad.loadString(ResourceIDs.IDS_MSGTITLE),
                JNotePad.loadString(ResourceIDs.IDS_MSGSAVEERR),
                box.STOP, UIButtonBar.OK);
            box.doModal();
        }

        // check if file is read only
        File fileObj = getFile();
        if (fileObj.canWrite())
        {
            setReadOnly(false);
        }
        else
        {
            setReadOnly(true);
        }

        // newly loaded files are clean (not dirty)
        setDirtyFlag(false);

        // restore the old cursor
        setCursor(iOldCursor);

        return ret;
    }

    /**
    *    Displays a wait cursor.
    *    @returns    The int ID of the cursor that used to be displayed
    */
    protected int showWaitCursor()
    {
        // return setCursor(Frame.WAIT_CURSOR);
        return 0;    // we don't show the cursor, becase the this.setCursor does nothing
    }

    /**
    *    Sets the cursor.
    *    @param    iCursor    The ID of the cursor to change to
    */
    protected int setCursor(int iCursor)
    {
        /*
        int iOldCursor = parentFrame.getFrame().getCursorType();

        parentFrame.getFrame().setCursor(iCursor);

        return iOldCursor;
        */
        return 0;
    }


    // searchReplace is done in parent class and not overridden
    // here

    // closeFile is done in parent class, no need to override

    // printFile is done in parent class, no need to override

}