Make control lines buttons react to line counts

Set the "apply" and "delete all" button sensitivity based on the number
of control lines. Add extra tooltip text to the apply button when
editing and there is not enough lines. The text explains there must be
enough vertical or horizontal control lines.

rtgui/controllines.cc

@@ -36,6 +36,7 @@ ControlLineManager::ControlLineManager():
     draw_mode(false),
     drawing_line(false),
     edited(false),
+    horizontalCount(0), verticalCount(0),
     prev_obj(-1),
     selected_object(-1)
 {
@@ -84,6 +85,16 @@ size_t ControlLineManager::size(void) const
     return control_lines.size();
 }
 
+size_t ControlLineManager::getHorizontalCount(void) const
+{
+    return horizontalCount;
+}
+
+size_t ControlLineManager::getVerticalCount(void) const
+{
+    return verticalCount;
+}
+
 bool ControlLineManager::button1Pressed(int modifierKey)
 {
     EditDataProvider* dataProvider = getEditProvider();
@@ -164,9 +175,13 @@ bool ControlLineManager::pick1(bool picked)
     if (line.type == rtengine::ControlLine::HORIZONTAL) {
         line.icon = line.icon_v;
         line.type = rtengine::ControlLine::VERTICAL;
+        horizontalCount--;
+        verticalCount++;
     } else if (line.type == rtengine::ControlLine::VERTICAL) {
         line.icon = line.icon_h;
         line.type = rtengine::ControlLine::HORIZONTAL;
+        horizontalCount++;
+        verticalCount--;
     }
 
     visibleGeometry[object_id - 1] = line.icon.get();
@@ -405,6 +420,11 @@ void ControlLineManager::addLine(Coord begin, Coord end,
     EditSubscriber::mouseOverGeometry.push_back(control_line->end.get());
 
     control_lines.push_back(std::move(control_line));
+    if (type == rtengine::ControlLine::HORIZONTAL) {
+        horizontalCount++;
+    } else {
+        verticalCount++;
+    }
 }
 
 void ControlLineManager::autoSetLineType(int object_id)
@@ -437,6 +457,13 @@ void ControlLineManager::autoSetLineType(int object_id)
     if (type != line.type) { // Need to update line type.
         line.type = type;
         line.icon = icon;
+        if (type == rtengine::ControlLine::HORIZONTAL) {
+            horizontalCount++;
+            verticalCount--;
+        } else {
+            horizontalCount--;
+            verticalCount++;
+        }
         visibleGeometry[line_id * ::ControlLine::OBJ_COUNT + 1] =
             line.icon.get();
     }
@@ -448,6 +475,7 @@ void ControlLineManager::removeAll(void)
     mouseOverGeometry.erase(mouseOverGeometry.begin() + 1,
                             mouseOverGeometry.end());
     control_lines.clear();
+    horizontalCount = verticalCount = 0;
     prev_obj = -1;
     selected_object = -1;
     edited = true;
@@ -470,6 +498,11 @@ void ControlLineManager::removeLine(size_t line_id)
         mouseOverGeometry.begin() + ::ControlLine::OBJ_COUNT * line_id
         + ::ControlLine::OBJ_COUNT + 1
     );
+    if (control_lines[line_id]->type == rtengine::ControlLine::HORIZONTAL) {
+        horizontalCount--;
+    } else {
+        verticalCount--;
+    }
     control_lines.erase(control_lines.begin() + line_id);
 
     edited = true;