Files
UnrealEngineUWP/Engine/Source/Editor/ReferenceViewer/Private/HistoryManager.h
2014-03-14 14:13:41 -04:00

92 lines
3.3 KiB
C++

// Copyright 1998-2014 Epic Games, Inc. All Rights Reserved.
#pragma once
/** The history data object, storing all important history data */
struct FReferenceViewerHistoryData
{
/** History Description */
FString HistoryDesc;
/** The list of package names to serve as the root */
TArray<FName> PackageNames;
};
/** The delegate for when history data should be applied */
DECLARE_DELEGATE_OneParam(FOnApplyHistoryData, const FReferenceViewerHistoryData& /*Data*/);
/** The delegate for when history data should be updated */
DECLARE_DELEGATE_OneParam(FOnUpdateHistoryData, FReferenceViewerHistoryData& /*Data*/);
/** The class responsible for managing all content browser history */
class FReferenceViewerHistoryManager
{
public:
/** Constructor */
FReferenceViewerHistoryManager();
/** Set the delegate for applying history data */
void SetOnApplyHistoryData(const FOnApplyHistoryData& InOnApplyHistoryData);
/** Set the delegate for updating history data */
void SetOnUpdateHistoryData(const FOnUpdateHistoryData& InOnUpdateHistoryData);
/** Goes back one history snapshot and returns the history data at that snapshot */
bool GoBack();
/** Goes forward one history snapshot and returns the history data at that snapshot */
bool GoForward();
/** Stores new history data. Called when creating a history snapshot */
void AddHistoryData();
/** Triggers an update for the current history data. This is typically done right before changing the history. */
void UpdateHistoryData();
/** Determines if a user can go forward in history */
bool CanGoForward() const;
/** Determines if a user can go back in history */
bool CanGoBack() const;
/** Gets the description of the previous history entry */
FString GetBackDesc() const;
/** Gets the description of the next history entry */
FString GetForwardDesc() const;
/**
* Populates a list of menu items that can be added to a context menu
* to allow a user to jump to different history snapshots instead of using the back and forward buttons
*
* @param bGetPrior If true gets history snapshots prior to the current history index(for navigating back). If false get history snapshots after the current history index (for navigating forward).
* @param MenuBuilder The menubuilder to populate with menu items
*/
void GetAvailableHistoryMenuItems(bool bGetPrior, FMenuBuilder& MenuBuilder);
private:
/** Notifies the owner to update to the state described by the current history data */
void ApplyCurrentHistoryData();
/** Notifies the owner to update the current history data */
void UpdateCurrentHistoryData();
/** Handler for when a history item is chosen in the GetAvailableHistroyMenuItems list */
void ExecuteJumpToHistory(int32 HistoryIndex);
private:
/** The delegate for when history data should be applied */
FOnApplyHistoryData OnApplyHistoryData;
/** The delegate for when history data should be updated */
FOnUpdateHistoryData OnUpdateHistoryData;
/** A list of history snapshots */
TArray<FReferenceViewerHistoryData> HistoryData;
/** The current history index the user is at (changes when the user goes back,forward, or history snapshots are taken) */
int32 CurrentHistoryIndex;
/** Max number of history items that can be stored. Once the max is reached, the oldest history item is removed */
int32 MaxHistoryEntries;
};