[escher] Create a class button

Change-Id: I6236925a4d8720d4e6e1c39483cf904d39d2031b

escher/Makefile

@@ -3,6 +3,7 @@ SFLAGS += -Iescher/include
 objs += $(addprefix escher/src/,\
   app.o\
   childless_view.o\
+  button.o\
   container.o\
   header_view_controller.o\
   image_view.o\

escher/include/escher.h

@@ -2,6 +2,7 @@
 #define ESCHER_H
 
 #include <escher/app.h>
+#include <escher/button.h>
 #include <escher/container.h>
 #include <escher/header_view_controller.h>
 #include <escher/image.h>

escher/include/escher/button.h

@@ -0,0 +1,27 @@
+#ifndef ESCHER_BUTTON_H
+#define ESCHER_BUTTON_H
+
+#include <escher/view.h>
+#include <escher/responder.h>
+#include <escher/text_view.h>
+#include <escher/invocation.h>
+
+class Button : public View, public Responder {
+public:
+  Button(Responder * parentResponder);
+  void drawRect(KDContext * ctx, KDRect rect) const override;
+  bool handleEvent(Ion::Events::Event event) override;
+  void setText(const char * textBody);
+  void setInvocation(Invocation invocation);
+  void setBackgroundColor(KDColor backgroundColor);
+  KDSize textSize();
+private:
+  int numberOfSubviews() const override;
+  View * subviewAtIndex(int index) override;
+  void layoutSubviews() override;
+  TextView m_textView;
+  Invocation m_invocation;
+  KDColor m_backgroundColor;
+};
+
+#endif

escher/src/button.cpp

@@ -0,0 +1,58 @@
+#include <escher/button.h>
+#include <assert.h>
+
+Button::Button(Responder * parentResponder) :
+  Responder(parentResponder),
+  m_textView(),
+  m_invocation(Invocation(nullptr, nullptr)),
+  m_backgroundColor(KDColorWhite)
+{
+  m_textView.setBackgroundColor(KDColorWhite);
+  m_textView.setTextColor(KDColorBlack);
+  m_textView.setAlignment(0.5f, 0.5f);
+}
+
+void Button::drawRect(KDContext * ctx, KDRect rect) const {
+  ctx->fillRect(rect, m_backgroundColor);
+}
+
+int Button::numberOfSubviews() const {
+  return 1;
+}
+
+View * Button::subviewAtIndex(int index) {
+  assert(index == 0);
+  return &m_textView;
+}
+
+void Button::layoutSubviews() {
+  m_textView.setFrame(bounds());
+}
+
+bool Button::handleEvent(Ion::Events::Event event) {
+  switch (event) {
+    case Ion::Events::Event::ENTER:
+      m_invocation.perform(this);
+      return true;
+    default:
+      return false;
+  }
+}
+
+void Button::setText(const char * textBody) {
+  m_textView.setText(textBody);
+}
+
+void Button::setInvocation(Invocation invocation) {
+  m_invocation = invocation;
+}
+
+void Button::setBackgroundColor(KDColor backgroundColor) {
+  m_backgroundColor = backgroundColor;
+  m_textView.setBackgroundColor(backgroundColor);
+  markRectAsDirty(bounds());
+}
+
+KDSize Button::textSize() {
+  return m_textView.textSize();
+}