add scroll-select layout - tested for each edge case and generic case

2 files changed, 284 insertions, 0 deletions

diff --git a/Layout/LayoutScrollSelect.cpp b/Layout/LayoutScrollSelect.cpp
new file mode 100644
index 0000000..5c7072e
--- /dev/null
+++ b/Layout/LayoutScrollSelect.cpp
@@ -0,0 +1,244 @@
+#include "LayoutScrollSelect.h"
+#include "MTSLog.h"
+
+LayoutScrollSelect::LayoutScrollSelect(DOGS102* lcd, Items items, std::string info1, std::string info2)
+  : Layout(lcd),
+    _lSw1(0, 7, "Scroll"),
+    _lSw2(11, 7, "Select"),
+    _lInfo1(0, 0, info1),
+    _lInfo2(0, 1, info2),
+    _lCursor(0, 4, "=>"),
+    _fItem1(3, 2, 14),
+    _fItem2(3, 3, 14),
+    _fItem3(3, 4, 14),
+    _fItem4(3, 5, 14),
+    _fItem5(3, 6, 14),
+    _items(items)
+{
+    _size = _items.size();
+    _selected = 0;
+}
+
+LayoutScrollSelect::~LayoutScrollSelect() {}
+
+void LayoutScrollSelect::display() {
+    clear();
+    startUpdate();
+
+    writeLabel(_lSw1);
+    writeLabel(_lSw2);
+    writeLabel(_lInfo1);
+    writeLabel(_lInfo2);
+    writeLabel(_lCursor);
+
+    switch (_size) {
+        case 0:
+            // special case - no items
+            //    (empty)
+            //    (empty)
+            // => (empty)
+            //    (empty)
+            //    (empty)
+            break;
+
+        case 1:
+            // special case - 1 item
+            //    (empty)
+            //    (empty)
+            // => item1
+            //    (empty)
+            //    (empty)
+            writeField(_fItem3, _items[0]);
+            break;
+
+        case 2:
+            // special case - 2 items
+            //    (empty)
+            //    (empty)
+            // => item1
+            //    item2
+            //    (empty)
+            writeField(_fItem3, _items[0]);
+            writeField(_fItem4, _items[1]);
+            break;
+
+        case 3:
+            // special case - 3 items
+            //    (empty)
+            //    item3
+            // => item1
+            //    item2
+            //    (empty)
+            writeField(_fItem2, _items[2]);
+            writeField(_fItem3, _items[0]);
+            writeField(_fItem4, _items[1]);
+            break;
+
+        case 4:
+            // special case - 4 items
+            //    item3
+            //    item4
+            // => item1
+            //    item2
+            //    (empty)
+            writeField(_fItem1, _items[2]);
+            writeField(_fItem2, _items[3]);
+            writeField(_fItem3, _items[0]);
+            writeField(_fItem4, _items[1]);
+            break;
+
+        default:
+            // this is the generic case - should handle lists of 5+ items correctly
+            //    item4         item6           item9
+            //    item5         item7           item10
+            // => item1      => item1        => item1
+            //    item2         item2           item2
+            //    item3         item3           item3
+            writeField(_fItem1, _items[_size - 2]);
+            writeField(_fItem2, _items[_size - 1]);
+            writeField(_fItem3, _items[0]);
+            writeField(_fItem4, _items[1]);
+            writeField(_fItem5, _items[2]);
+            break;
+    }
+
+    endUpdate();
+}
+
+void LayoutScrollSelect::scroll() {
+    size_t index;
+
+    switch (_size) {
+        case 0:
+        case 1:
+            // nothing to scroll
+            break;
+
+        case 2:
+            // special case - 2 items
+            //    (empty)  ->     (empty)
+            //    (empty)  ->     (empty)
+            // => item1    ->  => item2
+            //    item2    ->     item1
+            //    (empty)  ->     (empty)
+
+            index = _selected;
+            // keep selected item up to date
+            increment(_selected);
+
+            startUpdate();
+            // previously selected item moves down to field4
+            writeField(_fItem4, _items[index]);
+            increment(index);
+            // other item moves up to field3
+            writeField(_fItem3, _items[index]);
+            endUpdate();
+            break;
+
+        case 3:
+            // special case - 3 items
+            //    (empty)  ->     (empty)
+            //    item3    ->     item1  
+            // => item1    ->  => item2
+            //    item2    ->     item3
+            //    (empty)  ->     (empty)
+            
+            index = _selected;
+            // keep selected item up to date
+            increment(_selected);
+
+            startUpdate();
+            // previously selected item moves up to field2
+            writeField(_fItem2, _items[index]);
+            increment(index);
+            // new selected item moves up to field3
+            writeField(_fItem3, _items[index]);
+            increment(index);
+            // item from field2 moves down to field4
+            writeField(_fItem4, _items[index]);
+            endUpdate();
+            break;
+
+        case 4:
+            // special case - 4 items
+            //    item3    ->     item4  
+            //    item4    ->     item1  
+            // => item1    ->  => item2
+            //    item2    ->     item3
+            //    (empty)  ->     (empty)
+            
+            index = _selected;
+            // keep selected item up to date
+            increment(_selected);
+
+            startUpdate();
+            // previously selected item moves up to field2
+            writeField(_fItem2, _items[index]);
+            increment(index);
+            // new selected item moves up to field3
+            writeField(_fItem3, _items[index]);
+            increment(index);
+            // item from field1 moves down to field4
+            writeField(_fItem4, _items[index]);
+            increment(index);
+            // item from field2 moves up to field1
+            writeField(_fItem1, _items[index]);
+            endUpdate();
+            break;
+
+        default:
+            // this is the generic case - should handle lists of 5+ items correctly
+            //    item4    ->     item5           item6    ->     item7
+            //    item5    ->     item1           item7    ->     item1
+            // => item1    ->  => item2        => item1    ->  => item2
+            //    item2    ->     item3           item2    ->     item3
+            //    item3    ->     item4           item3    ->     item4
+            
+            index = _selected;
+            // keep selected item up to date
+            increment(_selected);
+
+            startUpdate();
+            decrement(index);
+            // item from field2 moves up to field1
+            writeField(_fItem1, _items[index]);
+            increment(index);
+            // previously selected item moves up to field2
+            writeField(_fItem2, _items[index]);
+            increment(index);
+            // new selected item moves up to field3
+            writeField(_fItem3, _items[index]);
+            increment(index);
+            // item from field5 moves up to field4
+            writeField(_fItem4, _items[index]);
+            increment(index);
+            // next item (from field1 or off screen) moves up to field5
+            writeField(_fItem5, _items[index]);
+            endUpdate();
+            break;
+      }
+}
+
+std::string LayoutScrollSelect::select() {
+    std::string selected = "";
+    if (_size > 0)
+        selected = _items[_selected];
+
+    return selected;
+}
+
+void LayoutScrollSelect::increment(size_t& index) {
+    if (_size > 1) {
+        index++;
+        index %= _size;
+    }
+}
+
+void LayoutScrollSelect::decrement(size_t& index) {
+    if (_size > 1) {
+        if (index == 0)
+            index = _size - 1;
+        else
+            index--;
+    }
+}
diff --git a/Layout/LayoutScrollSelect.h b/Layout/LayoutScrollSelect.h
new file mode 100644
index 0000000..4811ae5
--- /dev/null
+++ b/Layout/LayoutScrollSelect.h
@@ -0,0 +1,40 @@
+#ifndef __LAYOUTSCROLLSELECT_H__
+#define __LAYOUTSCROLLSELECT_H__
+
+#include "Layout.h"
+#include <vector>
+
+typedef std::vector<std::string> Items;
+
+class LayoutScrollSelect : public Layout {
+    public:
+        LayoutScrollSelect(DOGS102* lcd, Items items, std::string info1 = "", std::string info2 = "");
+        ~LayoutScrollSelect();
+
+        void display();
+
+        void scroll();
+        std::string select();
+
+    private:
+        void increment(size_t& index);
+        void decrement(size_t& index);
+
+        Label _lSw1;
+        Label _lSw2;
+        Label _lInfo1;
+        Label _lInfo2;
+        Label _lCursor;
+
+        Field _fItem1;
+        Field _fItem2;
+        Field _fItem3;
+        Field _fItem4;
+        Field _fItem5;
+
+        Items _items;
+        size_t _selected;
+        size_t _size;
+};
+
+#endif