fontpanel.java

一个小公司要求给写的很简单的任务管理系统。

        /// Draws one line of text at given position
        private void tlDrawLine( Graphics2D g2, TextLayout tl,
                                           float baseX, float baseY ) {
	    /// ABP - keep track of old tform, restore it later
	    AffineTransform oldTx = null;
	    oldTx = g2.getTransform();
  	    g2.translate( baseX, baseY );      	    
	    g2.transform( getAffineTransform( g2Transform ) );
    
            tl.draw( g2, (float) 0, (float) 0 );

	    /// ABP - restore old tform
    	    g2.setTransform ( oldTx );
            
        }


        /// If textToUse is set to range drawing, then convert
        /// int to hex string and prepends 0s to make it length 4
        /// Otherwise line number was fed; simply return number + 1 converted to String
        /// (This is because first line is 1, not 0)
        private String modeSpecificNumStr( int i ) {
            if ( textToUse == USER_TEXT || textToUse == FILE_TEXT )
              return String.valueOf( i + 1 );

            StringBuffer s = new StringBuffer( Integer.toHexString( i ));
            while ( s.length() < 4 )
              s.insert( 0, "0" );
            return s.toString().toUpperCase();
        }

        /// Resets the scrollbar to display correct range of text currently on screen
        /// (This scrollbar is not part of a "ScrollPane". It merely simulates its effect by
        ///  indicating the necessary area to be drawn within the panel.
        ///  By doing this, it prevents creating gigantic panel when large text range,
        ///  i.e. CJK Ideographs, is requested)
        private void resetScrollbar( int oldValue ) {
            int totalNumRows = 1, numCharToDisplay;
            if ( textToUse == RANGE_TEXT || textToUse == ALL_GLYPHS ) {
                if ( textToUse == RANGE_TEXT )
                  numCharToDisplay = drawRange[1] - drawRange[0];
                else /// textToUse == ALL_GLYPHS
                  numCharToDisplay = testFont.getNumGlyphs();

                totalNumRows = numCharToDisplay / numCharAcross;
                if ( numCharToDisplay % numCharAcross != 0 )
                  totalNumRows++;
                if ( oldValue / numCharAcross > totalNumRows )
                  oldValue = 0;

                verticalBar.setValues( oldValue / numCharAcross,
                                       numCharDown, 0, totalNumRows );
            }
            else {
                if ( textToUse == USER_TEXT )
                  totalNumRows = userText.length;
                else /// textToUse == FILE_TEXT;
                  totalNumRows = lineBreakTLs.size();
                verticalBar.setValues( oldValue, numCharDown, 0, totalNumRows );
            }
            if ( totalNumRows <= numCharDown && drawStart == 0) {
              verticalBar.setEnabled( false );
            }
            else {
              verticalBar.setEnabled( true );
            } 
        }

        /// Calculates the font's metrics that will be used for draw
        private void calcFontMetrics( Graphics2D g2d, int w, int h ) {
            FontMetrics fm;
            Graphics2D g2 = (Graphics2D)g2d.create();
            
            /// ABP
            if ( g2Transform != NONE && textToUse != FILE_TEXT ) {
                g2.setFont( g2.getFont().deriveFont( getAffineTransform( g2Transform )) );
            	fm = g2.getFontMetrics();
            }
            else {
            	fm = g2.getFontMetrics();
            }

            maxAscent = fm.getMaxAscent();
            maxDescent = fm.getMaxDescent();
	    if (maxAscent == 0) maxAscent = 10;
	    if (maxDescent == 0) maxDescent = 5;
            if ( textToUse == RANGE_TEXT || textToUse == ALL_GLYPHS ) {
                /// Give slight extra room for each character
                maxAscent += 3;
                maxDescent += 3;
                gridWidth = fm.getMaxAdvance() + 6;
                gridHeight = maxAscent + maxDescent;
                if ( force16Cols )
                  numCharAcross = 16;
                else
                  numCharAcross = ( w - 10 ) / gridWidth;
                numCharDown = ( h - 10 ) / gridHeight;

                canvasInset_X = ( w - numCharAcross * gridWidth ) / 2;
                canvasInset_Y = ( h - numCharDown * gridHeight ) / 2;
                if ( numCharDown == 0 || numCharAcross == 0 )
                  throw new CannotDrawException( isPrinting ? CANT_FIT_PRINT : CANT_FIT_DRAW );

                if ( !isPrinting )
                  resetScrollbar( verticalBar.getValue() * numCharAcross );
            }
            else {
                maxDescent += fm.getLeading();
                canvasInset_X = 5;
                canvasInset_Y = 5;
                /// gridWidth and numCharAcross will not be used in this mode...
                gridHeight = maxAscent + maxDescent;
                numCharDown = ( h - canvasInset_Y * 2 ) / gridHeight;

                if ( numCharDown == 0 )
                  throw new CannotDrawException( isPrinting ? CANT_FIT_PRINT : CANT_FIT_DRAW );
                /// If this is text loaded from file, prepares the LineBreak'ed
                /// text layout at this point
                if ( textToUse == FILE_TEXT ) {
                    if ( !isPrinting )
                      f2dt.fireChangeStatus( "LineBreaking Text... Please Wait", false );
                    lineBreakTLs = new Vector();
                    for ( int i = 0; i < fileText.length; i++ ) {
                        AttributedString as =
                          new AttributedString( fileText[i], g2.getFont().getAttributes() );

                        LineBreakMeasurer lbm =
                          new LineBreakMeasurer( as.getIterator(), g2.getFontRenderContext() );

                        while ( lbm.getPosition() < fileText[i].length() )
                          lineBreakTLs.add( lbm.nextLayout( (float) w ));

                    }
                }
                if ( !isPrinting )
                  resetScrollbar( verticalBar.getValue() );
            }
        }

        /// Calculates the amount of text that will be displayed on screen
        private void calcTextRange() {
            String displaying = null;

            if ( textToUse == RANGE_TEXT || textToUse == ALL_GLYPHS ) {
                if ( isPrinting )
                  if ( printMode == ONE_PAGE )
                    drawStart = currentlyShownChar;
                  else /// printMode == CUR_RANGE
                    drawStart = numCharAcross * numCharDown * printPageNumber;
                else
                  drawStart = verticalBar.getValue() * numCharAcross;
                if ( textToUse == RANGE_TEXT ) {
                    drawStart += drawRange[0];
                    drawLimit = drawRange[1];
                }
                else
                  drawLimit = testFont.getNumGlyphs();
                drawEnd = drawStart + numCharAcross * numCharDown - 1;

                if ( drawEnd >= drawLimit )
                  drawEnd = drawLimit;
            }
            else {
                if ( isPrinting )
                  if ( printMode == ONE_PAGE )
                    drawStart = currentlyShownChar;
                  else /// printMode == ALL_TEXT
                    drawStart = numCharDown * printPageNumber;
                else {
                    drawStart = verticalBar.getValue();
                }

                drawEnd = drawStart + numCharDown - 1;

                if ( textToUse == USER_TEXT )
                  drawLimit = userText.length - 1;
                else
                  drawLimit = lineBreakTLs.size() - 1;

                if ( drawEnd >= drawLimit )
                  drawEnd = drawLimit;
            }

            // ABP
            if ( drawStart > drawEnd ) {
              drawStart = 0;
              verticalBar.setValue(drawStart);
            }


            /// Change the status bar if not printing...
            if ( !isPrinting ) {
                backupStatusString = ( "Displaying" + MS_OPENING[textToUse] +
                                       modeSpecificNumStr( drawStart ) + " to " +
                                       modeSpecificNumStr( drawEnd ) +
                                       MS_CLOSING[textToUse] );
                f2dt.fireChangeStatus( backupStatusString, false );
            }
        }

        /// Draws text according to the parameters set by Font2DTest GUI
        private void drawText( Graphics g, int w, int h ) {
            Graphics2D g2;

            /// Create back buffer when not printing, and its Graphics2D
            /// Then set drawing parameters for that Graphics2D object
            if ( isPrinting )
              g2 = (Graphics2D) g;
            else  {
                backBuffer = (BufferedImage) this.createImage( w, h );
                g2 = backBuffer.createGraphics();
                g2.setColor(Color.white);
                g2.fillRect(0, 0, w, h);
                g2.setColor(Color.black);
            }
            
            /// sets font, RenderingHints.
            setParams( g2 );

            /// If flag is set, recalculate fontMetrics and reset the scrollbar
            if ( updateFontMetrics || isPrinting ) {
            	/// NOTE: re-calculates in case G2 transform
            	/// is something other than NONE
                calcFontMetrics( g2, w, h );
                updateFontMetrics = false;
            }
            /// Calculate the amount of text that can be drawn...
            calcTextRange();

            /// Draw according to the set "Text to Use" mode
            if ( textToUse == RANGE_TEXT || textToUse == ALL_GLYPHS ) {
                int charToDraw = drawStart;
                if ( showGrid )
                  drawGrid( g2 );
                if ( !isPrinting )
                  g.drawImage( backBuffer, 0, 0, this );

                for ( int i = 0; i < numCharDown && charToDraw <= drawEnd; i++ ) {
                  for ( int j = 0; j < numCharAcross && charToDraw <= drawEnd; j++, charToDraw++ ) {
                      int gridLocX = j * gridWidth + canvasInset_X;
                      int gridLocY = i * gridHeight + canvasInset_Y;

                      modeSpecificDrawChar( g2, charToDraw,
                                            gridLocX + gridWidth / 2,
                                            gridLocY + maxAscent );
                      //if ( !isPrinting ) {
                      //    g.setClip( gridLocX, gridLocY, gridWidth + 1, gridHeight + 1 );
                      //    g.drawImage( backBuffer, 0, 0, this );
			    //}

                  }
                }
            }
            else if ( textToUse == USER_TEXT ) {
                g2.drawRect( 0, 0, w - 1, h - 1 );
                if ( !isPrinting )
                  g.drawImage( backBuffer, 0, 0, this );

                for ( int i = drawStart; i <= drawEnd; i++ ) {
                    int lineStartX = canvasInset_Y;
                    int lineStartY = ( i - drawStart ) * gridHeight + maxAscent;
                    modeSpecificDrawLine( g2, userText[i], lineStartX, lineStartY );
                }
            }
            else {
                float xPos, yPos = (float) canvasInset_Y;
                g2.drawRect( 0, 0, w - 1, h - 1 );
                if ( !isPrinting )
                  g.drawImage( backBuffer, 0, 0, this );

                for ( int i = drawStart; i <= drawEnd; i++ ) {
                    TextLayout oneLine = (TextLayout) lineBreakTLs.elementAt( i );
                    xPos =
                      oneLine.isLeftToRight() ?
                      canvasInset_X : ( (float) w - oneLine.getAdvance() - canvasInset_X );
                    
                    float fmData[] = {0, oneLine.getAscent(), 0, oneLine.getDescent(), 0, oneLine.getLeading()};
                    if (g2Transform != NONE) {
                        AffineTransform at = getAffineTransform(g2Transform);
                        at.transform( fmData, 0, fmData, 0, 3);
                    }
                    //yPos += oneLine.getAscent();
                    yPos += fmData[1]; // ascent
                    //oneLine.draw( g2, xPos, yPos );
                    tlDrawLine( g2, oneLine, xPos, yPos );
                    //yPos += oneLine.getDescent() + oneLine.getLeading();
                    yPos += fmData[3] + fmData[5]; // descent + leading
                }
            }
		if ( !isPrinting )
                g.drawImage( backBuffer, 0, 0, this );
            g2.dispose();
        }

        /// Component paintComponent function...
        /// Draws/Refreshes canvas according to flag(s) set by other functions
        public void paintComponent( Graphics g ) {
            if ( updateBackBuffer ) {
                Dimension d = this.getSize();
                isPrinting = false;
                try {
                    drawText( g, d.width, d.height );
                }
                catch ( CannotDrawException e ) {
                    f2dt.fireChangeStatus( ERRORS[ e.id ], true );
                    super.paintComponent(g);
                    return;
                }
            }
            else {
              /// Screen refresh
              g.drawImage( backBuffer, 0, 0, this );
            }

            showingError = false;
            updateBackBuffer = false;
        }

        /// Printable interface function
        /// Component print function...
        public int print( Graphics g, PageFormat pf, int pageIndex ) {
            if ( pageIndex == 0 ) {
                /// Reset the last page index to max...
                lastPage = Integer.MAX_VALUE;
                currentlyShownChar = verticalBar.getValue() * numCharAcross;
            }

            if ( printMode == ONE_PAGE ) {
                if ( pageIndex > 0 )
                  return NO_SUCH_PAGE;
            }
            else {
                if ( pageIndex > lastPage )
                  return NO_SUCH_PAGE;
            }

            int pageWidth = (int) pf.getImageableWidth();
            int pageHeight = (int) pf.getImageableHeight();
            /// Back up metrics and other drawing info before printing modifies it
            int backupDrawStart = drawStart, backupDrawEnd = drawEnd;
            int backupNumCharAcross = numCharAcross, backupNumCharDown = numCharDown;
            Vector backupLineBreakTLs = null;
            if ( textToUse == FILE_TEXT )
              backupLineBreakTLs = (Vector) lineBreakTLs.clone();

            printPageNumber = pageIndex;
            isPrinting = true;