Add Table constructor from Elements. (#310)

CHANGELOG.md

@@ -20,6 +20,7 @@ unreleased (development)
   - `paragraphAlignJustify`
 - Add the helper elements based on `flexbox`: `hflow()`, `vflow()`.
 - Add: `focusPositionRelative` and `focusPosition`
+- Add `Table` constructor from 2D vector of Element, instead of string.
 
 #### Component 
 - Add the `collapsible` component.

include/ftxui/dom/table.hpp

@@ -33,7 +33,9 @@ class TableSelection;
 
 class Table {
  public:
+  Table();
   Table(std::vector<std::vector<std::string>>);
+  Table(std::vector<std::vector<Element>>);
   TableSelection SelectAll();
   TableSelection SelectCell(int column, int row);
   TableSelection SelectRow(int row_index);
@@ -47,6 +49,7 @@ class Table {
   Element Render();
 
  private:
+  void Initialize(std::vector<std::vector<Element>>);
   friend TableSelection;
   std::vector<std::vector<Element>> elements_;
   int input_dim_x_;

src/ftxui/dom/table.cpp

@@ -35,7 +35,27 @@ void Order(int& a, int& b) {
 
 }  // namespace
 
+Table::Table() {
+  Initialize({});
+}
+
 Table::Table(std::vector<std::vector<std::string>> input) {
+  std::vector<std::vector<Element>> output;
+  for(auto& row : input) {
+    output.push_back({});
+    auto& output_row = output.back();
+    for(auto& cell : row) {
+      output_row.push_back(text(cell));
+    }
+  }
+  Initialize(std::move(output));
+}
+
+Table::Table(std::vector<std::vector<Element>> input) {
+  Initialize(std::move(input));
+}
+
+void Table::Initialize(std::vector<std::vector<Element>> input) {
   input_dim_y_ = input.size();
   input_dim_x_ = 0;
   for (auto& row : input)
@@ -55,7 +75,7 @@ Table::Table(std::vector<std::vector<std::string>> input) {
     for (auto& row : input) {
       int x = 1;
       for (auto& cell : row) {
-        elements_[y][x] = text(cell);
+        elements_[y][x] = std::move(cell);
         x += 2;
       }
       y += 2;

src/ftxui/dom/table_test.cpp

@@ -12,7 +12,7 @@
 using namespace ftxui;
 
 TEST(TableTest, Empty) {
-  auto table = Table({});
+  auto table = Table();
   Screen screen(5, 5);
   Render(screen, table.Render());
   EXPECT_EQ(