Add ability to undo deleted dives

Before the dive is deleted, a copy is made and passed to the
undo buffer. When edit->undo is clicked, this dive is restored
to the dive list.

Signed-off-by: Grace Karanja <gracie.karanja89@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

qt-ui/divelistview.cpp

@@ -11,6 +11,7 @@
 #include <QSettings>
 #include <QFileDialog>
 #include "qthelper.h"
+#include "undobuffer.h"
 
 //                                #  Date  Rtg Dpth  Dur  Tmp Wght Suit  Cyl  Gas  SAC  OTU  CNS  Loc
 static int defaultWidth[] =    {  70, 140, 90,  50,  50,  50,  50,  70,  50,  50,  70,  50,  50, 500};
@@ -730,6 +731,9 @@ void DiveListView::deleteDive()
 	for_each_dive (i, d) {
 		if (!d->selected)
 			continue;
+		struct dive* undo_entry = alloc_dive();
+		copy_dive(get_dive(i), undo_entry);
+		MainWindow::instance()->undoBuffer->recordbefore("Delete Dive", undo_entry);
 		delete_single_dive(i);
 		i--; // so the next dive isn't skipped... it's now #i
 		lastDiveNr = i;

qt-ui/undobuffer.cpp

@@ -1,8 +1,9 @@
 #include "undobuffer.h"
+#include "mainwindow.h"
 
 UndoBuffer::UndoBuffer(QObject *parent) : QObject(parent)
 {
-
+	curIdx = 0;
 }
 
 UndoBuffer::~UndoBuffer()
@@ -12,32 +13,46 @@ UndoBuffer::~UndoBuffer()
 
 bool UndoBuffer::canUndo()
 {
-
+	return curIdx > 0;
 }
 
 bool UndoBuffer::canRedo()
 {
-
+	return curIdx < list.count();
 }
 
 void UndoBuffer::redo()
 {
-
+	current()->redo();
+	curIdx++;
+	if (curIdx > list.count())
+		curIdx = list.count() - 1;
 }
 
 void UndoBuffer::undo()
 {
-
+	current()->undo();
+	curIdx = list.indexOf(current());
 }
 
 void UndoBuffer::recordbefore(QString commandName, dive *affectedDive)
 {
-
+	UndoCommand *cmd = new UndoCommand(commandName, affectedDive);
+	//If we are within the list, clear the extra UndoCommands.
+	if (list.count() > 0) {
+		if (curIdx + 1 < list.count()) {
+			for (int i = curIdx + 1; i < list.count(); i++) {
+				list.removeAt(i);
+			}
+		}
+	}
+	list.append(cmd);
+	curIdx = list.count();
 }
 
 void UndoBuffer::recordAfter(dive *affectedDive)
 {
-
+	list.at(curIdx - 1)->setStateAfter(affectedDive);
 }
 
 
@@ -50,10 +65,14 @@ UndoCommand::UndoCommand(QString commandName, dive *affectedDive)
 
 void UndoCommand::undo()
 {
-
+	if (name == "Delete Dive") {
+		record_dive(stateBefore);
+		MainWindow::instance()->recreateDiveList();
+	}
 }
 
 void UndoCommand::redo()
 {
-
+	//To be implemented
 }
+

qt-ui/undobuffer.h

@@ -12,7 +12,7 @@ private:
 
 public:
 	explicit UndoCommand(QString commandName, dive* affectedDive);
-	void setStateAfter(dive* affectedDive);
+	void setStateAfter(dive* affectedDive) { stateAfter = affectedDive; }
 	void undo();
 	void redo();
 };
@@ -25,7 +25,9 @@ public:
 	~UndoBuffer();
 	bool canUndo();
 	bool canRedo();
+	UndoCommand *current() const { return list.at(curIdx - 1); }
 private:
+	QList<UndoCommand*> list;
 	int curIdx;
 public slots:
 	void redo();