@fractastical Paginator Controller

@fractastical Paginator Controller.txt

/* Joel Dietz
   jdietz@gmail.com
   03/26/2010
*/

public class TaskController {
	    
    public TaskPage activePage              { get; set; }
	public List<TaskPage> pages             { get; set; }
	public List<TaskPage> activePages       { get; set; }
	public Integer activePagesStartPNumber  { get; set; }
	public Integer activePagesEndPNumber    { get; set; }
	public Boolean hasMorePagesAfter        { get; set; }
	public Boolean hasMorePagesBefore       { get; set; }
	public Integer pnum                     { get; set; }
	public Integer tasksPerPage         	{ get; set; } 
 
    private static Integer pagesPerSetofActivePages = 10; 

	public TaskController() {
					  
		tasksPerPage = 10;		
		
	}
		
	public void loadAssignedTasks() {
		
		assignedTasks = null;  
		updateAssignedTasks();  
		                
        if (assignedTasks.size() > 0)
		{
		    pages = populatePages(assignedTasks, tasksPerPage);
	    	pnum = 1;
	        activePage = pages[0];
	        pages[0].isActive = true;
	    	updateActivePages();         	
        }
        else
        {
        	activePage = new taskPage(new List<ToDoItem__c>(),1);
        	activePage.first = true;    
        	activePage.last = true;  
        }  
	}
	
	
    public List<TaskPage> populatePages(List<ToDoItem__c> tasks, Integer ItemsPerPage) 
    {
        List<TaskPage> newPages = new List<TaskPage>();
        Integer tasksAdded = 0;
        Integer pagenumber = 0;
    
        // Adds tasks to TaskPages until either all tasks are added or the page limit is reached
        while(tasksAdded < tasks.size())       
        { 
            pagenumber++;
            List<ToDoItem__c> tasksToAdd = new List<ToDoItem__c>();
        
            for(Integer i=0; i < ItemsPerPage; i++) {
                
                if(tasksAdded == tasks.size())
                    break;
                    
                tasksToAdd.add(tasks[tasksAdded]);
                tasksAdded++;
                    
                }
                
            newPages.add(new TaskPage(tasksToAdd,pagenumber));
            if(pagenumber == 1) {
                newPages[0].first = true;
            }
            
            //DEPRECATED now that we have ActivePages 
            //if(pagenumber==pagesPerSetofActivePages)
            //    break;  
        
        }   
            
        newPages[pagenumber-1].last=true;
        
        return newPages;
    }
    
        
    public void updateActivePages() 
    {
        activePages = new List<TaskPage>();
        activePagesStartPNumber = pnum;
        Integer startIndex = pnum - 1;        
        Integer endIndex = startIndex + pagesPerSetofActivePages;
                    
        for (Integer i= startIndex; i < pages.size() && i < endIndex; i++)
            activePages.add(pages[i]);
        
        activePagesEndPNumber = activePages[activePages.size() - 1].pageNumber;

        if (activePagesEndPNumber == pages.size())
            hasMorePagesAfter = false;
        else 
            hasMorePagesAfter = true;  
                
        if (activePagesStartPNumber == 1)
            hasMorePagesBefore = false;
        else
            hasMorePagesBefore = true;
            
        setActivePage();
                                                       
    }

    public void updateActivePagesBackwards() 
    {
        List<TaskPage> tempActivePages = new List<TaskPage>();
        activePages = new List<TaskPage>();

        activePagesEndPNumber = pnum;
        Integer endIndex = pnum - 1;
        Integer startIndex = endIndex - pagesPerSetofActivePages - 1;        

        for (Integer i= endIndex; (i >= 0) && (i > startIndex); i--)
            tempActivePages.add(pages[i]);    
            
        for(Integer i = (tempActivePages.size() - 1); i >= 0; i--) {
            //System.debug('i:' + i);
            activePages.add(tempActivePages[i]);
        }  
                    
        activePagesStartPNumber = activePages[0].pageNumber;
        
        if (activePagesEndPNumber == pages.size())
            hasMorePagesAfter = false;
        else 
            hasMorePagesAfter = true;
                
        if (activePagesStartPNumber == 1)  
            hasMorePagesBefore = false;
        else
            hasMorePagesBefore = true;
            
        setActivePage();
                                       
    }
    
    public PageReference updatetasksPerPage() 
    {
        pnum = 1;
        pages = populatePages(assignedTasks, tasksPerPage);
        activePage = pages[0];   
        pages[0].isActive = true;
    	updateActivePages();  
          
        return null;    
    }
    
    public void setActivePage() 
    {
        Integer oldPN = activePage.pageNumber;
        activePage = pages[pnum - 1];
        pages[oldPN - 1].isActive = false;
        pages[pnum - 1].isActive = true;
    }

        
    public void updateActivePage()
    {
        setActivePage();
        if (pnum > activePagesEndPNumber)
            updateActivePages();
        if (pnum < activePagesStartPNumber)
            updateActivePagesBackwards();           
    }
        
    public void goToLast()
    {
        if (pages != null && pages.size() > 0)
            pnum = pages.size()-1;
        updateActivePage();
        
    }
            
    public List<SelectOption> gettasksPerPageSO()
    {
    	List<SelectOption> bbpso = new List<SelectOption>();
    	bbpso.add(new SelectOption('1','1'));
    	bbpso.add(new SelectOption('2','2'));
    	bbpso.add(new SelectOption('5','5'));
    	bbpso.add(new SelectOption('10','10'));
    	bbpso.add(new SelectOption('20','20'));
    	bbpso.add(new SelectOption('50','50'));
    	return bbpso;  
    }
    
    public void nextPage()
    {
      if (!activePage.last) 
        pnum = activePage.pageNumber + 1;
      updateActivePage();  
    }
    
   public void prevPage()
   {
      if (!activePage.first)
        pnum = activePage.pageNumber - 1;
      updateActivePage();
    }
    
    
    class TaskPage 
    {  
  
        public Boolean first 			{get; set;}
        public Boolean last 			{get; set;}
        public List <ToDoItem__c> pageTasks {get; set;}
        public Integer pageNumber 		{get; set;}
        public Boolean isActive 		{get; set;}

        public TaskPage(List <ToDoItem__c> mi, Integer pn)
        {
            pageTasks = mi;   
            pageNumber = pn;
            isActive = false;
            first = false;
            last = false;
        }  
        
    }
    
    static testMethod void testTaskPages()
	{
			User tu = TestUtility.createTestUser();
			System.runAs(tu) 
			{
				TaskController tc = new TaskController();
				List<ToDoItem__c> testTasks = new List<ToDoItem__c>();
				ToDoItem__c sampleTask;
				String descr = 'D' + math.rint(math.random() * 10000);
				for(Integer i=0; i < 41; i++) 
				{
					sampleTask = new ToDoItem__c();
					sampleTask.name = 'Test Task ' + i;
					sampleTask.description__c = descr;
					sampleTask.assigned_to__c = tu.id;
					sampleTask.managed_by__c = tu.id;
					testTasks.add(sampleTask);
				}
				insert testTasks;
				tc.queryItemLimit = 41;
				tc.loadAssignedTasks();
				System.assertEquals(41, tc.getAssignedTasks().size());
				System.assertEquals(5, tc.ActivePages.size());
				System.assert(tc.ActivePage.first);
				System.assertEquals(false, tc.ActivePage.last);
				System.assertEquals(false, tc.hasMorePagesAfter);
				System.assertEquals(false, tc.hasMorePagesBefore);
				tc.tasksPerPage = 2;
				tc.updatetasksPerPage();
				System.assertEquals(21, tc.pages.size());
				tc.pnum = 15;
				tc.updateActivePage();
				System.assert(tc.hasMorePagesBefore);
				System.assertEquals(false,tc.hasMorePagesAfter);
				System.assertEquals(false, tc.ActivePage.last);
				System.assertEquals(false, tc.ActivePage.first);
				tc.pnum = 21;
				tc.updateActivePage();
				System.assert(tc.hasMorePagesBefore);
				System.assert(tc.ActivePage.last);
				System.assertEquals(false,tc.hasMorePagesAfter);
				System.assertEquals(false, tc.ActivePage.first);
		}
	}
				
    	
}