DisplayController.m

/*
     File: DisplayController.m
 Abstract: A window controller to display the titles of the text snippets.
 
  Version: 1.1
 
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 Neither the name, trademarks, service marks or logos of Apple Inc. may
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 without specific prior written permission from Apple.  Except as
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 The Apple Software is provided by Apple on an "AS IS" basis.  APPLE
 MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION
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 FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND
 OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.
 
 IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL
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 */

#import "AppDelegate.h"
#import "DisplayController.h"
#import "Step.h"

@implementation DisplayController


@synthesize arrayController, tableView;


#pragma mark -
#pragma mark Services methods

-(NSString *)textForCurrentSelectionAndAdvance {
    
    NSString *string = nil;
    NSUInteger selectedRow = [arrayController selectionIndex];
    
    if (selectedRow != NSNotFound) {
        Step *step = (Step *)[[arrayController arrangedObjects] objectAtIndex:selectedRow];
        string = step.body;
        if (string == nil) {
            string = @"";
        }
        [self moveDownOneLine];
    }
    else {
        string = @"";
    }
    return string;
}


- (void)rewind {
    [tableView selectRowIndexes:[NSIndexSet indexSetWithIndex:0] byExtendingSelection:NO];
    [tableView scrollRowToVisible:0];
}


- (void)moveUpOneLine {
    NSUInteger selectedRow = [arrayController selectionIndex];
    if ((selectedRow > 0) && (selectedRow != NSNotFound)) {
        [tableView selectRowIndexes:[NSIndexSet indexSetWithIndex:(selectedRow -1)] byExtendingSelection:NO];
        [tableView scrollRowToVisible:(selectedRow -1)];
    }
}


- (void)moveDownOneLine {
    
    NSUInteger selectedRow = [arrayController selectionIndex];
    if (selectedRow == NSNotFound) {
        return;
    }
    selectedRow++;
    if (selectedRow < [[arrayController arrangedObjects] count]) {
        [arrayController setSelectionIndex:selectedRow];    
        [tableView scrollRowToVisible:selectedRow];
    }
}


#pragma mark -
#pragma mark Table view delegate methods

- (NSString *)tableView:(NSTableView *)aTableView toolTipForCell:(NSCell *)aCell rect:(NSRectPointer)rect tableColumn:(NSTableColumn *)aTableColumn row:(NSInteger)row mouseLocation:(NSPoint)mouseLocation {
    
    // If user defaults allows tooltips, then return the step's tooltip.
    
    if ([[[[NSUserDefaultsController sharedUserDefaultsController]
        values] valueForKey:DMKDisplayToolTipsKey] boolValue]) {
        Step *step = (Step *)[[arrayController arrangedObjects] objectAtIndex:row];
        return step.tooltip;
    }
    return nil;
}


- (BOOL)tableView:(NSTableView *)aTableView shouldSelectRow:(NSInteger)rowIndex {
    
    // For convenience, automatically write the row to the pasteboard then make sure the next row is displayed, ready for the next selection.
    BOOL ok = [self writeRow:rowIndex toPasteboard:[NSPasteboard generalPasteboard]];
    if (ok && (rowIndex < [[arrayController arrangedObjects] count] -1)) {
        [self performSelector:@selector(scrollTableViewToRow:) withObject:[NSNumber numberWithInteger:(rowIndex+1)] afterDelay:0.1];
    }
    return ok;
}


- (BOOL)tableView:(NSTableView *)tv writeRowsWithIndexes:(NSIndexSet *)rowIndexes toPasteboard:(NSPasteboard*)pboard {
    
    // Don't write anything if more than one row is selected.
    if ([rowIndexes count] != 1) {
        return NO;
    }
    
    NSInteger row = [rowIndexes firstIndex];
    if (row < [[arrayController arrangedObjects] count] -1) {
        [self performSelector:@selector(scrollTableViewToRow:) withObject:[NSNumber numberWithInteger:(row+1)] afterDelay:0.1];
    }
    return [self writeRow:row toPasteboard:pboard];
}


#pragma mark -
#pragma mark Table view drag and drop

/*
 The display table view shouldn't support drag and drop or any reordering.
 */
- (NSDragOperation)tableView:(NSTableView*)tv validateDrop:(id <NSDraggingInfo>)info proposedRow:(NSInteger)row proposedDropOperation:(NSTableViewDropOperation)op {
    return NSDragOperationNone;
}


- (BOOL)tableView:(NSTableView*)tv acceptDrop:(id <NSDraggingInfo>)info row:(NSInteger)row dropOperation:(NSTableViewDropOperation)op {
    return NO;
}


#pragma mark -
#pragma mark Scroll to view

- (void)scrollTableViewToRow:(NSNumber *)row {
    [tableView scrollRowToVisible:[row integerValue]];    
}


#pragma mark -
#pragma mark Writing rows

- (BOOL)writeRow:(NSInteger)row toPasteboard:(NSPasteboard*)pboard {
    
    // For the display window, just write the selected step's body, not the complete step.
    Step *step = (Step *)[[arrayController arrangedObjects] objectAtIndex:row];
    NSString *stepBody = step.body;
    if (stepBody == nil) {
        return NO;
    }
    
    [pboard clearContents];
    [pboard writeObjects:[NSArray arrayWithObject:stepBody]];
    return YES;
}


#pragma mark -
#pragma mark Window transparency

/*
 Observe the shared user defaults controller for changes to the displayWindowAlpha preference.
 Update the window's alpha value in response.
 */

static const NSString *windowAlphaContext;

- (void)windowDidLoad {
    
    [super windowDidLoad];
    [tableView setDraggingSourceOperationMask:NSDragOperationCopy forLocal:NO];
    
    NSUserDefaultsController *udc = [NSUserDefaultsController sharedUserDefaultsController];
    
    NSString *displayWindowAlphaKeyPath = [@"values." stringByAppendingString:DMKDisplayWindowAlphaKey];
    [udc addObserver:self forKeyPath:displayWindowAlphaKeyPath options:0 context:&windowAlphaContext];
    
    [[self window] setAlphaValue:[[udc valueForKeyPath:displayWindowAlphaKeyPath] floatValue]];
}


- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
    
    if (context != &windowAlphaContext) {
        [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
        return;
    }
    [[self window] setAlphaValue:[[object valueForKeyPath:[@"values." stringByAppendingString:DMKDisplayWindowAlphaKey]] floatValue]];
}



#pragma mark -
#pragma mark Object lifecycle
         
- (void) dealloc {
    NSUserDefaultsController *udc = [NSUserDefaultsController sharedUserDefaultsController];
    [udc removeObserver:self forKeyPath:[@"values." stringByAppendingString:DMKDisplayWindowAlphaKey]];
    [super dealloc];    
}

@end