- Add an initial barebones version of the history controller, with a basic toolbar item to navigate backwards and forwards. TBC!

1 files changed, 256 insertions, 0 deletions

diff --git a/Source/SPHistoryController.m b/Source/SPHistoryController.m
new file mode 100644
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+++ b/Source/SPHistoryController.m
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+//
+//  $Id: SPFieldEditorController.h 802 2009-06-03 20:46:57Z bibiko $
+//
+//  SPHistoryController.h
+//  sequel-pro
+//
+//  Created by Rowan Beentje on July 23, 2009
+//
+//  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+//  More info at <http://code.google.com/p/sequel-pro/>
+
+#import "TableDocument.h"
+#import "TablesList.h"
+#import "SPHistoryController.h"
+
+
+@implementation SPHistoryController
+
+#pragma mark Setup and teardown
+
+/**
+ * Initialise by creating a blank history array
+ */
+- (id) init
+{
+	if (self = [super init]) {
+		history = [[NSMutableArray alloc] init];
+		historyPosition = NSNotFound;
+		restoringHistoryState = NO;
+	}
+	return self;	
+}
+
+- (void) dealloc
+{
+	[history release];
+	[super dealloc];
+}
+
+#pragma mark -
+#pragma mark Interface interaction
+
+/**
+ * Updates the toolbar item to reflect the current history state and position
+ */
+- (void) updateToolbarItem
+{
+	BOOL backEnabled = NO;
+	BOOL forwardEnabled = NO;
+
+	// Set the active state of the segments if appropriate
+	if ([history count] && historyPosition > 0) backEnabled = YES;
+	if ([history count] && historyPosition + 1 < [history count]) forwardEnabled = YES;
+	
+	[historyControl setEnabled:backEnabled forSegment:0];
+	[historyControl setEnabled:forwardEnabled forSegment:1];
+}
+
+/**
+ * Trigger a navigation action in response to a click
+ */
+- (IBAction) historyControlClicked:(NSSegmentedControl *)theControl
+{
+	switch ([theControl selectedSegment]) {
+
+		// Back button clicked:
+		case 0:
+			if (historyPosition == NSNotFound || !historyPosition) return;
+			[self loadEntryAtPosition:historyPosition - 1];
+			break;
+
+		// Forward button clicked:
+		case 1:
+			if (historyPosition == NSNotFound || historyPosition + 1 >= [history count]) return;
+			[self loadEntryAtPosition:historyPosition + 1];
+			break;
+	}
+}
+
+/**
+ * Retrieve the view that is currently selected from the database
+ */
+- (unsigned int) currentlySelectedView
+{
+	unsigned int theView = NSNotFound;
+
+	NSString *viewName = [[[theDocument valueForKey:@"tableTabView"] selectedTabViewItem] identifier];
+	if ([viewName isEqualToString:@"source"]) {
+		theView = SP_VIEW_STRUCTURE;
+	} else if ([viewName isEqualToString:@"content"]) {
+		theView = SP_VIEW_CONTENT;
+	} else if ([viewName isEqualToString:@"customQuery"]) {
+		theView = SP_VIEW_CUSTOMQUERY;
+	} else if ([viewName isEqualToString:@"status"]) {
+		theView = SP_VIEW_STATUS;
+	} else if ([viewName isEqualToString:@"relations"]) {
+		theView = SP_VIEW_RELATIONS;
+	}
+
+	return theView;
+}
+
+#pragma mark -
+#pragma mark Adding or updating history entries
+
+/**
+ * Call to store or update a history item for the document state. Checks against
+ * the latest stored details; if they match, a new history item is not created.
+ * This should therefore be called without worry of duplicates.
+ */
+- (void) updateHistoryEntries
+{
+
+	// Don't modify anything if we're in the process of restoring an old history state
+	if (restoringHistoryState) return;
+
+	// Work out the current document details
+	NSString *theDatabase = [theDocument database];
+	NSString *theTable = [theDocument table];
+	unsigned int theView = [self currentlySelectedView];
+
+	// Check for a duplicate against the current entry
+	if (historyPosition != NSNotFound) {
+		NSDictionary *currentHistoryItem = [history objectAtIndex:historyPosition];
+		if ([[currentHistoryItem objectForKey:@"database"] isEqualToString:theDatabase]
+			&& [[currentHistoryItem objectForKey:@"table"] isEqualToString:theTable]
+			&& [[currentHistoryItem objectForKey:@"view"] intValue] == theView)
+		{
+			return;
+		}
+	}
+
+	// If there's any items after the current history position, remove them
+	if (historyPosition != NSNotFound && historyPosition < [history count] - 1) {
+		[history removeObjectsInRange:NSMakeRange(historyPosition + 1, [history count] - historyPosition - 1)];
+
+	// Special case: if the last history item is currently active, and has no table,
+	// but the new selection does - delete the last entry, in order to replace it.
+	// This improves history flow.
+	} else if (historyPosition != NSNotFound && historyPosition == [history count] - 1
+				&& [[[history objectAtIndex:historyPosition] objectForKey:@"database"] isEqualToString:theDatabase]
+				&& ![[history objectAtIndex:historyPosition] objectForKey:@"table"])
+	{
+		[history removeLastObject];		
+	}
+
+	// Construct and add the new history entry
+	NSMutableDictionary *newEntry = [NSMutableDictionary dictionaryWithObjectsAndKeys:
+										theDatabase, @"database",
+										theTable, @"table",
+										[NSNumber numberWithInt:theView], @"view",
+										nil];
+	[history addObject:newEntry];
+	historyPosition = [history count] - 1;
+	[self updateToolbarItem];
+}
+
+#pragma mark -
+#pragma mark Loading history entries
+
+/**
+ * Load a history entry and attempt to return the interface to that state.
+ */
+- (void) loadEntryAtPosition:(unsigned int)position
+{
+
+	// Sanity check the input
+	if (position == NSNotFound || position < 0 || position >= [history count]) {
+		NSBeep();
+		return;
+	}
+
+	restoringHistoryState = YES;
+
+	// Update the position and extract the history entry
+	historyPosition = position;
+	NSDictionary *historyEntry = [history objectAtIndex:historyPosition];
+
+	// Check and set the database
+	if (![[theDocument database] isEqualToString:[historyEntry objectForKey:@"database"]]) {
+		NSPopUpButton *chooseDatabaseButton = [theDocument valueForKey:@"chooseDatabaseButton"];
+		[chooseDatabaseButton selectItemWithTitle:[historyEntry objectForKey:@"database"]];
+		[theDocument chooseDatabase:self];
+		if (![[theDocument database] isEqualToString:[historyEntry objectForKey:@"database"]]) {
+			return [self abortEntryLoad];
+		}
+	}
+
+	// Check and set the table
+	if ([historyEntry objectForKey:@"table"] && ![[theDocument table] isEqualToString:[historyEntry objectForKey:@"table"]]) {
+		TablesList *tablesListInstance = [theDocument valueForKey:@"tablesListInstance"];
+		NSArray *tables = [tablesListInstance tables];
+		if ([tables indexOfObject:[historyEntry objectForKey:@"table"]] == NSNotFound) {
+			return [self abortEntryLoad];
+		}
+		[[tablesListInstance valueForKey:@"tablesListView"] selectRowIndexes:[NSIndexSet indexSetWithIndex:[tables indexOfObject:[historyEntry objectForKey:@"table"]]] byExtendingSelection:NO];
+		if (![[theDocument table] isEqualToString:[historyEntry objectForKey:@"table"]]) {
+			return [self abortEntryLoad];
+		}
+	} else if (![historyEntry objectForKey:@"table"] && [theDocument table]) {
+		TablesList *tablesListInstance = [theDocument valueForKey:@"tablesListInstance"];
+		[[tablesListInstance valueForKey:@"tablesListView"] deselectAll:self];		
+	}
+
+	// Check and set the view
+	if ([self currentlySelectedView] != [[historyEntry objectForKey:@"view"] intValue]) {
+		switch ([[historyEntry objectForKey:@"view"] intValue]) {
+			case SP_VIEW_STRUCTURE:
+				[theDocument viewStructure:self];
+				break;
+			case SP_VIEW_CONTENT:
+				[theDocument viewContent:self];
+				break;
+			case SP_VIEW_CUSTOMQUERY:
+				[theDocument viewQuery:self];
+				break;
+			case SP_VIEW_STATUS:
+				[theDocument viewStatus:self];
+				break;
+			case SP_VIEW_RELATIONS:
+				[theDocument viewRelations:self];
+				break;
+		}
+		if ([self currentlySelectedView] != [[historyEntry objectForKey:@"view"] intValue]) {
+			return [self abortEntryLoad];
+		}
+	}
+
+	restoringHistoryState = NO;
+	[self updateToolbarItem];
+}
+
+/**
+ * Convenience method for aborting history load - could at some point
+ * clean up the history list, show an alert, etc
+ */
+- (void) abortEntryLoad
+{
+	NSBeep();
+	restoringHistoryState = NO;
+}
+
+@end