[apps] TextFieldWithExtension blocks cursor on the rightmost text

apps/shared/Makefile

@@ -76,6 +76,7 @@ app_objs += $(addprefix apps/shared/,\
   tab_table_controller.o\
   text_field_delegate.o\
   text_field_delegate_app.o\
+  text_field_with_extension.o\
   toolbox_helpers.o\
   values_function_parameter_controller.o\
   values_parameter_controller.o\

apps/shared/text_field_with_extension.cpp

@@ -0,0 +1,14 @@
+#include "text_field_with_extension.h"
+
+namespace Shared {
+
+void TextFieldWithExtension::willSetCursorLocation(int * location) {
+  size_t textLength = strlen(text());
+  assert(textLength >= m_extensionLength);
+  size_t maxLocation = textLength - m_extensionLength;
+  if (*location > (int)maxLocation) {
+    *location = maxLocation;
+  }
+}
+
+}

apps/shared/text_field_with_extension.h

@@ -0,0 +1,32 @@
+#ifndef SHARED_TEXT_FIELD_WITH_EXTENSION_H
+#define SHARED_TEXT_FIELD_WITH_EXTENSION_H
+
+#include <escher/text_field.h>
+
+namespace Shared {
+
+class TextFieldWithExtension : public TextField {
+public:
+  TextFieldWithExtension(size_t extensionLength,
+      Responder * parentResponder,
+      char * textBuffer,
+      char * draftTextBuffer,
+      size_t textBufferSize,
+      TextFieldDelegate * delegate = nullptr,
+      bool hasTwoBuffers = true,
+      KDText::FontSize size = KDText::FontSize::Large,
+      float horizontalAlignment = 0.0f,
+      float verticalAlignment = 0.5f,
+      KDColor textColor = KDColorBlack,
+      KDColor backgroundColor = KDColorWhite) :
+    TextField(parentResponder, textBuffer, draftTextBuffer, textBufferSize, delegate, hasTwoBuffers, size, horizontalAlignment, verticalAlignment, textColor, backgroundColor),
+    m_extensionLength(extensionLength)
+  {}
+private:
+  void willSetCursorLocation(int * location) override;
+  size_t m_extensionLength;
+};
+
+}
+
+#endif

escher/include/escher/text_input.h

@@ -55,6 +55,7 @@ protected:
   virtual const ContentView * nonEditableContentView() const = 0;
 private:
   virtual TextInputDelegate * delegate() = 0;
+  virtual void willSetCursorLocation(int * location) {}
 };
 
 #endif

escher/src/text_input.cpp

@@ -12,8 +12,8 @@ TextInput::ContentView::ContentView(const KDFont * font) :
 }
 
 void TextInput::ContentView::setCursorLocation(int location) {
-  int adjustedLocation = location < 0 ? 0 : location;
-  adjustedLocation = adjustedLocation > (signed int)editedTextLength() ? (signed int)editedTextLength() : adjustedLocation;
+  assert(location >= 0);
+  int adjustedLocation = location > (signed int)editedTextLength() ? (signed int)editedTextLength() : location;
   m_cursorIndex = adjustedLocation;
   layoutSubviews();
 }
@@ -84,7 +84,9 @@ void TextInput::scrollToCursor() {
 }
 
 bool TextInput::setCursorLocation(int location) {
-  contentView()->setCursorLocation(location);
+  int adjustedLocation = location < 0 ? 0 : location;
+  willSetCursorLocation(&adjustedLocation);
+  contentView()->setCursorLocation(adjustedLocation);
   scrollToCursor();
   return true;
 }