Integrating Our RTF Class into MathPaper

Now that we have defined the RTF class, let’s integrate it into the MathPaper application to get the promised fonts and formatting:

  1. Open MathPaper.pbproj in Project Builder and choose File → New File to create a new file called RTF.h.

  2. Select Empty File in the New File Assistant pane and then click Next.

  3. Enter “RTF.h” in the File Name field, make sure the MathPaper target is checked, and then click Finish.

  4. Now enter the RTF class interface code, as provided in the previous section, into RTF.h.

  5. Similarly, create another file called RTF.m and insert the RTF class implementation code (also provided earlier) into it.

  6. If they aren’t there already, drag the RTF.h and RTF.m files into the Classes group in PB’s Groups & Files pane.

Tip

Another way to perform the six steps presented in this section is to first create the RTF.h and RTF.m class files outside of PB, using another editor (e.g., TextEdit or GNU Emacs). Save these two files in the ~/MathPaper folder, and then drag their file icons from the Finder and drop them into the Classes group in PB’s Groups & Files pane.

Now that our new RTF class has been added to the project, we proceed to make the necessary changes in the PaperController class.

  1. Insert the following directive after the other #import statement near the top of PaperController.m: 

                         #import "RTF.h"

  2. Insert the new appendRTFData: method declaration shown here into the existing NSTextView(MathPaper) category interface: 

    @interface NSTextView(MathPaper)
- (void)appendString:(NSString *)str;- (void)appendRTFData:(NSData *)str;
@end

  3. Insert the new appendRTFData: method implementation shown here into the NSTextView(MathPaper) category implementation: 

                         - (void)appendRTFData:(NSData *)data
                     {
                         int len = [ [self string] length];
                         [self replaceCharactersInRange:NSMakeRange(len,0) withRTF:data];
                     }

  4. Replace the gotData: method implementation in PaperController.m with the new implementation shown here: 

                         #define USE_RTF
                     - (void)gotData:(NSNotification *)not
                     {
                         NSData      *data;
                         NSString    *str;
                     #ifdef USE_RTF
                         RTF         *rtf  = [[[RTF alloc] init] autorelease];
                     #endif

    data = [ [not userInfo]
              objectForKey:NSFileHandleNotificationDataItem];
    str  = [ [NSString alloc] initWithData:data
                                  encoding:NSASCIIStringEncoding];

    [str autorelease];    /* Automatically release when done */

    // Add the data to the end of the text object#ifdef USE_RTF
                         [rtf setBold:YES];
                         [rtf setJustify:NSRightTextAlignment];
                         [rtf setSize:20];
                         [rtf appendString:str];
                         [rtf setBold:NO];
                         [rtf setJustify:NSLeftTextAlignment];
                         [rtf setSize:12];
                         [rtf appendString:@"--------------------
"];
                         [theText appendRTFData:[rtf data]];
                     #else
                         [theText appendString:str];
                         [theText appendString:@"--------------------
"];
                     #endif
                         // Now scroll to the bottom
                         [theText scrollRangeToVisible:
                                  NSMakeRange([[theText textStorage] length], 0)];
                         // Register to get the notification again
                         [fromEvaluator readInBackgroundAndNotify];
                         // Finally, allow the user to make any changes to the text
                         [theText setEditable:YES];
                     }

Notice that we used the USE_RTF conditional compilation technique so that RTF can be turned off when desired without doing a lot of editing. This is a useful technique when you are developing code. Second, notice that we alloc, init, and autorelease the RTF string all in one place. This assures that the string will be properly freed when we are done using it; we don’t have to bother with a separate release message.

  1. Save all pertinent files, and build and run your MathPaper project. The RTF object should behave as shown in the screen shot on the left in the earlier Figure 12-1.

  2. Quit MathPaper.

..................Content has been hidden....................

You can't read the all page of ebook, please click here login for view all page.
Reset
3.138.37.151