[escher] make an independent class alternate empty view to handle

empty store and add a delegate to the header view controller class

Change-Id: I7c4e8342876e9273270772d4bad0db9424276a98

escher/src/alternate_empty_view_controller.cpp

@@ -0,0 +1,78 @@
+#include <escher/alternate_empty_view_controller.h>
+#include <escher/app.h>
+#include <escher/palette.h>
+#include <assert.h>
+
+/* ContentView */
+
+AlternateEmptyViewController::ContentView::ContentView(ViewController * mainViewController, AlternateEmptyViewDelegate * delegate) :
+  m_message(PointerTextView(nullptr, 0.5f, 0.5f, KDColorBlack, Palette::BackgroundColor)),
+  m_mainViewController(mainViewController),
+  m_delegate(delegate)
+{
+}
+
+void AlternateEmptyViewController::ContentView::drawRect(KDContext * ctx, KDRect rect) const {
+  if (m_delegate->isEmpty()) {
+    ctx->fillRect(bounds(), Palette::BackgroundColor);
+  }
+}
+
+int AlternateEmptyViewController::ContentView::numberOfSubviews() const {
+  return 1;
+}
+
+View * AlternateEmptyViewController::ContentView::subviewAtIndex(int index) {
+  assert(index == 0);
+  if (m_delegate->isEmpty()) {
+    m_message.setText(m_delegate->emptyMessage());
+    return &m_message;
+  }
+  return m_mainViewController->view();
+}
+
+void AlternateEmptyViewController::ContentView::layoutSubviews() {
+  m_message.setFrame(bounds());
+  m_mainViewController->view()->setFrame(bounds());
+}
+
+ViewController * AlternateEmptyViewController::ContentView::mainViewController() const {
+  return m_mainViewController;
+}
+
+AlternateEmptyViewDelegate * AlternateEmptyViewController::ContentView::alternateEmptyViewDelegate() const {
+  return m_delegate;
+}
+
+/* AlternateEmptyViewController */
+
+AlternateEmptyViewController::AlternateEmptyViewController(Responder * parentResponder, ViewController * mainViewController, AlternateEmptyViewDelegate * delegate) :
+  ViewController(parentResponder),
+  m_contentView(ContentView(mainViewController, delegate))
+{
+}
+
+View * AlternateEmptyViewController::view() {
+  return &m_contentView;
+}
+
+const char * AlternateEmptyViewController::title() const {
+  return m_contentView.mainViewController()->title();
+}
+
+bool AlternateEmptyViewController::handleEvent(Ion::Events::Event event) {
+  if (m_contentView.alternateEmptyViewDelegate()->isEmpty()) {
+    if (event != Ion::Events::Home) {
+      app()->setFirstResponder(m_contentView.alternateEmptyViewDelegate()->defaultController());
+      return true;
+    }
+    return false;
+  }
+  return false;
+}
+
+void AlternateEmptyViewController::didBecomeFirstResponder() {
+  if (!m_contentView.alternateEmptyViewDelegate()->isEmpty()) {
+    app()->setFirstResponder(m_contentView.mainViewController());
+  }
+}