/* GrandPerspective, Version 2.5.4 
 *   A utility for Mac OS X that graphically shows disk usage. 
 * Copyright (C) 2005-2020, Erwin Bonsma 
 * 
 * This program is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU General Public License as published by the Free 
 * Software Foundation; either version 2 of the License, or (at your option) 
 * any later version. 
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT 
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for 
 * more details. 
 * 
 * You should have received a copy of the GNU General Public License along 
 * with this program; if not, write to the Free Software Foundation, Inc., 
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA. 
 */

#import "DrawTaskExecutor.h"

#import "TreeDrawer.h"
#import "TreeDrawerSettings.h"
#import "DrawTaskInput.h"
#import "TreeContext.h"


@implementation DrawTaskExecutor

// Overrides designated initialiser
- (instancetype) init {
  NSAssert(NO, @"Use initWithTreeContext: instead.");
  return [self initWithTreeContext: nil];
}


- (instancetype) initWithTreeContext:(TreeContext *)treeContextVal {
  return [self initWithTreeContext: treeContextVal 
                   drawingSettings: [[[TreeDrawerSettings alloc] init] autorelease]];
}

- (instancetype) initWithTreeContext:(TreeContext *)treeContextVal
                     drawingSettings:(TreeDrawerSettings *)settings {
  if (self = [super init]) {
    treeContext = [treeContextVal retain];
  
    treeDrawer = [[TreeDrawer alloc] initWithScanTree: [treeContext scanTree]
                                   treeDrawerSettings: settings];
    treeDrawerSettings = [settings retain];
    
    settingsLock = [[NSLock alloc] init];
  }
  return self;
}

- (void) dealloc {
  [treeContext release];

  [treeDrawer release];
  [treeDrawerSettings release];
  
  [settingsLock release];
  
  [super dealloc];
}


- (TreeDrawerSettings *)treeDrawerSettings {
  return treeDrawerSettings;
}

- (void) setTreeDrawerSettings:(TreeDrawerSettings *)settings {
  [settingsLock lock];
  if (settings != treeDrawerSettings) {
    [treeDrawerSettings release];
    treeDrawerSettings = [settings retain];
  }
  [settingsLock unlock];
}


- (void) prepareToRunTask {
  [treeDrawer clearAbortFlag];
}

- (id) runTaskWithInput:(id)input {
  [settingsLock lock];
  // Even though the settings are immutable, obtaining the settingsLock
  // ensures that it is not de-allocated while it is being used. 
  [treeDrawer updateSettings: treeDrawerSettings];
  [settingsLock unlock];

  DrawTaskInput  *drawingInput = input;
    
  [treeContext obtainReadLock];
    
  NSImage  *image = [treeDrawer drawImageOfVisibleTree: [drawingInput visibleTree]
                                        startingAtTree: [drawingInput treeInView]
                                    usingLayoutBuilder: [drawingInput layoutBuilder]
                                                inRect: [drawingInput bounds]];

  [treeContext releaseReadLock];

  return image;
}

- (void) abortTask {
  [treeDrawer abortDrawing];
}

@end
