<apex:page showHeader="false" sidebar="false" standardController="Hotel_Menu_Item__c" extensions="MenuTMS" recordSetVar="htlMenu">
    <apex:form >
        <apex:pageBlock title="Menu Items">
            <apex:outputText >Hello!</apex:outputText>
            <br/><br/>
            <apex:pageBlockTable value="{! htlMenu }" var="htl" cellspacing="10px" cellpadding="10px">
                <apex:column value="{! htl.Name }" />
                <apex:column value="{! htl.Price__c }" />
                <apex:column > <apex:inputText style="width: 50px" value="{!htl.Quantity__c}" /> </apex:column>
            </apex:pageBlockTable>
            <apex:pageBlockButtons >
                <apex:commandButton action="{!save}" value="Save" />
            </apex:pageBlockButtons>
        </apex:pageBlock>
    </apex:form>
</apex:page>


public class MenuTMS {
    public List <Hotel_Menu_Item__c> ItemDetails { get; set;}
    
    public ApexPages.StandardSetController stdSetController {get; set;}
    
    public ApexPages.StandardController stdController {get; set;}
    
    public static PageReference save(){
        
        List <Hotel_Menu_Item__c> ItemDetails = [SELECT Id,Name,Price__c,Quantity__c FROM Hotel_Menu_Item__c WHERE Quantity__c != NULL];
        
		List <Double> Amount = new List <Double> ();
        for(Integer i = 0; i < ItemDetails.size(); i++){
            Amount.add((ItemDetails[i].Price__c) * (ItemDetails[i].Quantity__c));
        }
        
        UPDATE ItemDetails;
        
        List <Invoice__c> invoice = new List <Invoice__c>();
        
        for(Invoice__c inv: invoice){
            for(Integer j = 0; j < ItemDetails.size(); j++){
                inv.Name__c = ItemDetails[j].Name;
                inv.Price__c = ItemDetails[j].Price__c;
                inv.Quantity__c = ItemDetails[j].Quantity__c;
                inv.Amount__c = Amount[j];
            }
        }
        
        INSERT invoice;
        
/*        for(Integer j = 0; j < ItemDetails.size(); j++){
            Invoice__c inv = new Invoice__c();
	        inv.Name = Hotel_Menu_Item__c.Name;
        }	*/
        
        PageReference pageRef = new PageReference('/apex/TMSMenuBillPage');
        pageRef.setRedirect(true);
        return pageRef;
        
    }
    
/*    public static PageReference gotoMenu(){
        PageReference pageRef = new PageReference('apex/TMSMenu');
        pageRef.setRedirect(true);
        return pageRef;
    }	*/
    
    public MenuTMS(){
        ItemDetails = [SELECT Id,Name,Price__c,Quantity__c FROM Hotel_Menu_Item__c WHERE Quantity__c != NULL];
		List <Double> Amount = new List <Double> ();
        for(Integer i = 0; i < ItemDetails.size(); ++i){
            Amount.add((ItemDetails[i].Price__c) * (ItemDetails[i].Quantity__c));
        }
        System.debug(ItemDetails);
    }
    
/*    public static void clearList(){
        //Code to clear the Name and price fields.
    } */
    
    public MenuTMS(ApexPages.StandardSetController controller){
        stdSetController = controller;
    }
    
    public MenuTMS(ApexPages.StandardController controller){
        stdController = controller;
    }
    
}