[ion/clipboard] Use system clipboard on simulator

Add methods to interface Epsilon's clipboard with the system's when
running a simulator.
Note that the clipboard still uses a buffer located in the
Escher::Clipboard class, as some features require a buffer to execute
computations on the clipboard's content.

Change-Id: I14c19615805d38735e64d481c617863db22db9bc

escher/src/clipboard.cpp

@@ -1,5 +1,6 @@
 #include <escher/clipboard.h>
 #include <escher/text_field.h>
+#include <ion/clipboard.h>
 #include <algorithm>
 
 static Clipboard s_clipboard;
@@ -10,9 +11,12 @@ Clipboard * Clipboard::sharedClipboard() {
 
 void Clipboard::store(const char * storedText, int length) {
   strlcpy(m_textBuffer, storedText, length == -1 ? TextField::maxBufferSize() : std::min(TextField::maxBufferSize(), length + 1));
+  Ion::Clipboard::write(m_textBuffer);
 }
 
 const char * Clipboard::storedText() {
+  Ion::Clipboard::read(m_textBuffer, TextField::maxBufferSize());
+
   /* In order to allow copy/paste of empty formulas, we need to add empty
    * layouts between empty system parenthesis. This way, when the expression
    * is parsed, it is recognized as a proper formula and appears with the correct
@@ -39,6 +43,8 @@ const char * Clipboard::storedText() {
 
 void Clipboard::reset() {
   strlcpy(m_textBuffer, "", 1);
+  /* As we do not want to empty the user's computer's clipboard when entering
+   * exam mode, we do not reset Ion::Clipboard. */
 }
 
 void Clipboard::replaceCharForPython(bool entersPythonApp) {

ion/include/ion.h

@@ -3,6 +3,7 @@
 
 #include <ion/backlight.h>
 #include <ion/battery.h>
+#include <ion/clipboard.h>
 #include <ion/console.h>
 #include <ion/display.h>
 #include <ion/events.h>

ion/include/ion/clipboard.h

@@ -0,0 +1,18 @@
+#ifndef ION_CLIPBOARD_H
+#define ION_CLIPBOARD_H
+
+#include <stddef.h>
+
+namespace Ion {
+namespace Clipboard {
+
+/* Write the text to the system clipboard. */
+void write(const char * text);
+
+/* Fill the buffer with text from the system clipboard. */
+void read(char * buffer, size_t bufferSize);
+
+}
+}
+
+#endif

ion/src/device/shared/drivers/Makefile

@@ -3,6 +3,7 @@ ion_device_src += $(addprefix ion/src/device/shared/drivers/, \
   battery.cpp \
   base64.cpp \
   board.cpp \
+  clipboard.cpp \
   console_uart.cpp:+consoleuart \
   console_dummy.cpp:-consoleuart \
   crc32.cpp \

ion/src/device/shared/drivers/clipboard.cpp

@@ -0,0 +1,11 @@
+#include <ion/clipboard.h>
+
+namespace Ion {
+
+/* Dummy implementation
+ * On the device, the clipboard is fully handled by Escher::Clipboard. */
+
+void Clipboard::write(const char * text) {}
+void Clipboard::read(char * buffer, size_t bufferSize) {}
+
+}

ion/src/simulator/Makefile

@@ -8,6 +8,7 @@ ion_src += $(addprefix ion/src/simulator/shared/, \
   dummy/serial_number.cpp \
   dummy/stack.cpp \
   dummy/usb.cpp \
+  clipboard.cpp \
   console_stdio.cpp:-consoledisplay \
   crc32.cpp \
   display.cpp:-headless \

ion/src/simulator/shared/clipboard.cpp

@@ -0,0 +1,24 @@
+#include <ion/clipboard.h>
+#include <SDL.h>
+#include <string.h>
+
+namespace Ion {
+
+void Clipboard::write(const char * text) {
+  /* FIXME : Handle the error if need be. */
+  SDL_SetClipboardText(text);
+}
+
+void Clipboard::read(char * buffer, size_t bufferSize) {
+  if (!SDL_HasClipboardText()) {
+    buffer[0] = '\0';
+    return;
+  }
+  char * text = SDL_GetClipboardText();
+  if (text) {
+    strlcpy(buffer, text, bufferSize);
+    SDL_free(text);
+  }
+}
+
+}