Mobile: Generate DiveObjectHelpers on the fly

Instead of keeping track of a list of DiveObjectHelpers, generate
them on-the-fly in DiveListModel. Thus, there is less danger of
model and core getting out of sync. On the flip-side, now the
DiveListModel and the DiveListSortModel might get out of sync.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

2 files changed, 12 insertions, 0 deletions

diff --git a/core/subsurface-qt/DiveObjectHelper.cpp b/core/subsurface-qt/DiveObjectHelper.cpp
index c19c03eb4..cb6cf6dd1 100644
--- a/core/subsurface-qt/DiveObjectHelper.cpp
+++ b/core/subsurface-qt/DiveObjectHelper.cpp
@@ -67,6 +67,16 @@ DiveObjectHelper::DiveObjectHelper(struct dive *d) :
 {
 }
 
+DiveObjectHelper::operator bool() const
+{
+	return !!m_dive;
+}
+
+bool DiveObjectHelper::operator!() const
+{
+	return !m_dive;
+}
+
 int DiveObjectHelper::number() const
 {
 	return m_dive->number;
diff --git a/core/subsurface-qt/DiveObjectHelper.h b/core/subsurface-qt/DiveObjectHelper.h
index 7071c1580..674386e56 100644
--- a/core/subsurface-qt/DiveObjectHelper.h
+++ b/core/subsurface-qt/DiveObjectHelper.h
@@ -50,6 +50,8 @@ class DiveObjectHelper {
 public:
 	DiveObjectHelper(); // This is only to be used by Qt's metatype system!
 	DiveObjectHelper(struct dive *dive);
+	operator bool() const; // Returns false if this is an invalid default-generated object
+	bool operator!() const; // Returns true if this is an invalid default-generated object
 	int number() const;
 	int id() const;
 	struct dive *getDive() const;