Add the ability for keys to be drawn as an image.

services/keyboard_native/key_layout.cc

Index: services/keyboard_native/key_layout.cc
diff --git a/services/keyboard_native/key_layout.cc b/services/keyboard_native/key_layout.cc
index 13957cb4b7ba347c43712b0a58fc89489b868c6b..546edc2fa843b4b0222837ca7107d686cf349cfb 100644
--- a/services/keyboard_native/key_layout.cc
+++ b/services/keyboard_native/key_layout.cc
@@ -5,9 +5,14 @@
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/macros.h"
+#include "services/keyboard_native/kActionIcon.h"
+#include "services/keyboard_native/kDeleteIcon.h"
+#include "services/keyboard_native/kLowerCaseIcon.h"
+#include "services/keyboard_native/kUpperCaseIcon.h"
 #include "services/keyboard_native/key_layout.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkTypeface.h"
+#include "ui/gfx/codec/png_codec.h"
 
 namespace keyboard {
 
@@ -20,6 +25,7 @@ KeyLayout::TextKey::TextKey(
 KeyLayout::TextKey::~TextKey() {
 }
 
+// Key implementation.

[viettrungluu, 2015/06/02 22:29:35]

You can probably skip this comment in the .cc file.

[APW, 2015/06/02 23:16:55]

Done.

 void KeyLayout::TextKey::Draw(SkCanvas* canvas,
                               SkPaint paint,
                               const gfx::RectF& rect) {
@@ -36,6 +42,56 @@ void KeyLayout::TextKey::OnTouchUp() {
   touch_up_callback_.Run(*this);
 }
 
+KeyLayout::ImageKey::ImageKey(
+    const char* text,
+    base::Callback<void(const TextKey&)> touch_up_callback,
+    const mojo::embed::Data& data)
+    : text_key_(text, touch_up_callback), bitmap_valid_(false), bitmap_() {
+  bool result = gfx::PNGCodec::Decode(
+      reinterpret_cast<const unsigned char*>(data.data), data.size, &bitmap_);
+  DCHECK(result);
+  if (result) {
+    DCHECK(bitmap_.width() > 0);

[viettrungluu, 2015/06/02 22:29:35]

nit: DCHECK_GT (though I suppose if it fails, you know that bitmap_.width() is
zero, so <shrug>)

[APW, 2015/06/02 23:16:54]

Done.

+    DCHECK(bitmap_.height() > 0);
+    bitmap_valid_ = bitmap_.width() > 0 && bitmap_.height() > 0;

[viettrungluu, 2015/06/02 22:29:35]

... though personally I might just do:

bitmap_valid_ = result && bitmap_.width() > 0 && bitmap_.height() > 0;
DCHECK(bitmap_valid_);

[APW, 2015/06/02 23:16:54]

Done.

+  }
+}
+
+KeyLayout::ImageKey::~ImageKey() {
+}
+
+// Key implementation.

[viettrungluu, 2015/06/02 22:29:35]

...

[APW, 2015/06/02 23:16:55]

Done.

+void KeyLayout::ImageKey::Draw(SkCanvas* canvas,
+                               SkPaint paint,
+                               const gfx::RectF& rect) {
+  // If our bitmap is somehow invalid, default to drawing the text of the key.
+  if (!bitmap_valid_) {
+    text_key_.Draw(canvas, paint, rect);
+    return;
+  }
+
+  float width_scale = rect.width() / bitmap_.width();
+  float height_scale = rect.height() / bitmap_.height();
+  float scale = width_scale > height_scale ? height_scale : width_scale;
+  float target_width = bitmap_.width() * scale;
+  float target_height = bitmap_.height() * scale;
+  float delta_width = rect.width() - target_width;
+  float target_x = rect.x() + (delta_width / 2.0f);
+  float delta_height = rect.height() - target_height;
+  float target_y = rect.y() + (delta_height / 2.0f);
+  canvas->drawBitmapRect(bitmap_, SkRect::MakeXYWH(target_x, target_y,
+                                                   target_width, target_height),
+                         &paint);
+}
+
+const char* KeyLayout::ImageKey::ToText() const {
+  return text_key_.ToText();
+}
+
+void KeyLayout::ImageKey::OnTouchUp() {
+  text_key_.OnTouchUp();
+}
+
 KeyLayout::KeyLayout()
     : on_text_callback_(),
       layout_(&letters_layout_),
@@ -199,6 +255,15 @@ void KeyLayout::InitKeyMaps() {
   base::Callback<void(const TextKey&)> switch_to_symbols_callback =
       base::Bind(&KeyLayout::OnKeySwitchToSymbols, weak_factory_.GetWeakPtr());
 
+  ImageKey* switch_to_upper_case_image_key = new ImageKey(
+      "/\\", switch_to_upper_case_callback, keyboard_native::kUpperCaseIcon);
+  ImageKey* switch_to_lower_case_image_key = new ImageKey(
+      "\\/", switch_to_lower_case_callback, keyboard_native::kLowerCaseIcon);
+  ImageKey* delete_image_key =
+      new ImageKey("<-", delete_callback, keyboard_native::kDeleteIcon);
+  ImageKey* action_image_key =
+      new ImageKey(":)", do_nothing_callback, keyboard_native::kActionIcon);
+
   std::vector<Key*> lower_case_key_map_row_one = {
       new TextKey("q", emit_text_callback),
       new TextKey("w", emit_text_callback),
@@ -223,7 +288,7 @@ void KeyLayout::InitKeyMaps() {
       new TextKey("l", emit_text_callback)};
 
   std::vector<Key*> lower_case_key_map_row_three = {
-      new TextKey("/\\", switch_to_upper_case_callback),
+      switch_to_upper_case_image_key,
       new TextKey("z", emit_text_callback),
       new TextKey("x", emit_text_callback),
       new TextKey("c", emit_text_callback),
@@ -231,14 +296,14 @@ void KeyLayout::InitKeyMaps() {
       new TextKey("b", emit_text_callback),
       new TextKey("n", emit_text_callback),
       new TextKey("m", emit_text_callback),
-      new TextKey("del", delete_callback)};
+      delete_image_key};
 
   std::vector<Key*> lower_case_key_map_row_four = {
       new TextKey("sym", switch_to_symbols_callback),
       new TextKey(",", emit_text_callback),
       new TextKey(" ", emit_text_callback),
       new TextKey(".", emit_text_callback),
-      new TextKey("act", do_nothing_callback)};
+      action_image_key};
 
   lower_case_key_map_ = {lower_case_key_map_row_one,
                          lower_case_key_map_row_two,
@@ -269,7 +334,7 @@ void KeyLayout::InitKeyMaps() {
       new TextKey("L", emit_text_callback)};
 
   std::vector<Key*> upper_case_key_map_row_three = {
-      new TextKey("\\/", switch_to_lower_case_callback),
+      switch_to_lower_case_image_key,
       new TextKey("Z", emit_text_callback),
       new TextKey("X", emit_text_callback),
       new TextKey("C", emit_text_callback),
@@ -277,14 +342,14 @@ void KeyLayout::InitKeyMaps() {
       new TextKey("B", emit_text_callback),
       new TextKey("N", emit_text_callback),
       new TextKey("M", emit_text_callback),
-      new TextKey("DEL", delete_callback)};
+      delete_image_key};
 
   std::vector<Key*> upper_case_key_map_row_four = {
       new TextKey("SYM", switch_to_symbols_callback),
       new TextKey(",", emit_text_callback),
       new TextKey(" ", emit_text_callback),
       new TextKey(".", emit_text_callback),
-      new TextKey("ACT", do_nothing_callback)};
+      action_image_key};
 
   upper_case_key_map_ = {upper_case_key_map_row_one,
                          upper_case_key_map_row_two,
@@ -323,7 +388,7 @@ void KeyLayout::InitKeyMaps() {
       new TextKey(";", emit_text_callback),
       new TextKey("!", emit_text_callback),
       new TextKey("?", emit_text_callback),
-      new TextKey("del", delete_callback)};
+      delete_image_key};
 
   std::vector<Key*> symbols_key_map_row_four = {
       new TextKey("ABC", switch_to_lower_case_callback),
@@ -332,7 +397,7 @@ void KeyLayout::InitKeyMaps() {
       new TextKey(" ", emit_text_callback),
       new TextKey("/", emit_text_callback),
       new TextKey(".", emit_text_callback),
-      new TextKey("act", do_nothing_callback)};
+      action_image_key};
 
   symbols_key_map_ = {symbols_key_map_row_one,
                       symbols_key_map_row_two,