Render text/highlight selected text on the canvas

Now we don't render the default ui::Entry edges, but we paint just a
border of the text bounds + the rendered text highlighting selected
text on the canvas itself.

With this change click mouse positions are translated with a scale
factor that changes depending on the app::Editor zoom.

src/app/ui/editor/writing_text_state.cpp

@@ -35,6 +35,12 @@
 #include "ui/message.h"
 #include "ui/paint_event.h"
 
+#ifdef LAF_SKIA
+  #include "app/util/shader_helpers.h"
+  #include "os/skia/skia_helpers.h"
+  #include "os/skia/skia_surface.h"
+#endif
+
 namespace app {
 
 using namespace ui;
@@ -82,7 +88,13 @@ public:
     m_doc->generateMaskBoundaries();
   }
 
-  ExtraCelRef extraCel() const { return m_extraCel; }
+  // Returns the extra cel with the text rendered (but without the
+  // selected text highlighted).
+  ExtraCelRef extraCel() {
+    renderExtraCelBase();
+    renderExtraCelText(false);
+    return m_extraCel;
+  }
 
 private:
   bool onProcessMessage(Message* msg) override {
@@ -112,36 +124,48 @@ private:
   }
 
   void onPaint(PaintEvent& ev) override {
-    Entry::onPaint(ev);
+    Graphics* g = ev.graphics();
+
+    // Don't paint the base Entry borders
+    //Entry::onPaint(ev);
+
     if (!hasText())
       return;
 
+    // Paint border
+    {
+      ui::Paint paint;
+      paint.style(ui::Paint::Stroke);
+      set_checkered_paint_mode(paint, 0,
+                               gfx::rgba(0, 0, 0, 255),
+                               gfx::rgba(255, 255, 255, 255));
+      g->drawRect(clientBounds(), paint);
+    }
+
     try {
-      text::TextBlobRef blob = textBlob();
-      if (!blob) {
+      if (!textBlob()) {
         m_doc->setExtraCel(nullptr);
         m_editor->invalidate();
         return;
       }
 
-      const auto textColor =
-        color_utils::color_for_image(
-          Preferences::instance().colorBar.fgColor(),
-          IMAGE_RGB);
+      // Render extra cel with text + selected text
+      renderExtraCelBase();
+      renderExtraCelText(true);
+      m_doc->setExtraCel(m_extraCel);
 
-      doc::ImageRef image = render_text_blob(blob, textColor);
-      if (image) {
-        renderExtraCelBase();
+      // Paint caret
+      if (isCaretVisible()) {
+        int scroll, caret;
+        getEntryThemeInfo(&scroll, &caret, nullptr, nullptr);
 
-        doc::blend_image(
-          m_extraCel->image(), image.get(),
-          gfx::Clip(image->bounds().size()),
-          m_doc->sprite()->palette(m_editor->frame()),
-          255, doc::BlendMode::NORMAL);
-
-        m_doc->setExtraCel(m_extraCel);
-        m_editor->invalidate();
+        gfx::RectF caretBounds = getCharBoxBounds(caret);
+        caretBounds *= gfx::SizeF(scale());
+        caretBounds.w = 1;
+        g->fillRect(gfx::rgba(0, 0, 0), caretBounds);
       }
+
+      m_editor->invalidate();
     }
     catch (const std::exception& e) {
       StatusBar::instance()->showTip(500, std::string(e.what()));
@@ -159,6 +183,50 @@ private:
       doc::BlendMode::SRC);
   }
 
+  void renderExtraCelText(const bool withSelection) {
+    const auto textColor =
+      color_utils::color_for_image(
+        Preferences::instance().colorBar.fgColor(),
+        IMAGE_RGB);
+
+    text::TextBlobRef blob = textBlob();
+    if (!blob)
+      return;
+
+    doc::ImageRef image = render_text_blob(blob, textColor);
+    if (!image)
+      return;
+
+    // Invert selected range in the image
+    if (withSelection) {
+      Range range;
+      getEntryThemeInfo(nullptr, nullptr, nullptr, &range);
+      if (!range.isEmpty()) {
+        gfx::RectF selectedBounds =
+          getCharBoxBounds(range.from) |
+          getCharBoxBounds(range.to-1);
+
+        if (!selectedBounds.isEmpty()) {
+#ifdef LAF_SKIA
+          sk_sp<SkSurface> skSurface = wrap_docimage_in_sksurface(image.get());
+          os::SurfaceRef surface = base::make_ref<os::SkiaSurface>(skSurface);
+
+          os::Paint paint;
+          paint.blendMode(os::BlendMode::Xor);
+          paint.color(textColor);
+          surface->drawRect(selectedBounds, paint);
+#endif // LAF_SKIA
+        }
+      }
+    }
+
+    doc::blend_image(
+      m_extraCel->image(), image.get(),
+      gfx::Clip(image->bounds().size()),
+      m_doc->sprite()->palette(m_editor->frame()),
+      255, doc::BlendMode::NORMAL);
+  }
+
   Editor* m_editor;
   Doc* m_doc;
   ExtraCelRef m_extraCel;
@@ -178,7 +246,7 @@ WritingTextState::WritingTextState(Editor* editor,
     App::instance()->contextBar()->FontChange.connect(
       &WritingTextState::onFontChange, this);
 
-  m_entry->setBounds(calcEntryBounds());
+  onEditorResize(editor);
 }
 
 WritingTextState::~WritingTextState()
@@ -232,8 +300,11 @@ bool WritingTextState::onKeyUp(Editor*, KeyMessage* msg)
   return true;
 }
 
-void WritingTextState::onEditorResize(Editor*)
+void WritingTextState::onEditorResize(Editor* editor)
 {
+  const gfx::PointF scale(editor->projection().scaleX(),
+                          editor->projection().scaleY());
+  m_entry->setScale(scale);
   m_entry->setBounds(calcEntryBounds());
 }
 

src/app/util/render_text.cpp

@@ -25,6 +25,7 @@
 
 #ifdef LAF_SKIA
   #include "app/util/shader_helpers.h"
+  #include "os/skia/skia_helpers.h"
   #include "os/skia/skia_surface.h"
 #endif
 

src/ui/entry.cpp

@@ -52,6 +52,7 @@ Entry::Entry(const int maxsize, const char* format, ...)
   , m_recent_focused(false)
   , m_lock_selection(false)
   , m_translate_dead_keys(true)
+  , m_scale(1.0f, 1.0f)
 {
   enableFlags(CTRL_RIGHT_CLICK);
 
@@ -235,6 +236,16 @@ gfx::Rect Entry::getEntryTextBounds() const
   return onGetEntryTextBounds();
 }
 
+gfx::Rect Entry::getCharBoxBounds(const int charBoxIndex)
+{
+  int i = 0;
+  int x = 0;
+  for (; i<charBoxIndex; ++i) {
+    x += m_boxes[i].width;
+  }
+  return gfx::Rect(x, 0, m_boxes[i].width, textHeight());
+}
+
 bool Entry::onProcessMessage(Message* msg)
 {
   switch (msg->type()) {
@@ -551,9 +562,9 @@ gfx::Rect Entry::onGetEntryTextBounds() const
   return bounds;
 }
 
-int Entry::getCaretFromMouse(MouseMessage* mousemsg)
+int Entry::getCaretFromMouse(MouseMessage* mouseMsg)
 {
-  int mouseX = mousemsg->position().x;
+  const int mouseX = mouseMsg->position().x;
   if (mouseX < bounds().x+border().left()) {
     // Scroll to the left
     return std::max(0, m_scroll-1);
@@ -569,7 +580,8 @@ int Entry::getCaretFromMouse(MouseMessage* mousemsg)
       indexBox = j+1;
     }
 
-    int x = bounds().x + border().left() + segmentWidth + m_boxes[indexBox].width / 2;
+    const int x = bounds().x + border().left()
+      + (segmentWidth + m_boxes[indexBox].width / 2) * m_scale.x;
 
     if (mouseX > bounds().x2() - border().right()) {
       if (x >= bounds().x2() - border().right()) {

src/ui/entry.h

@@ -63,6 +63,9 @@ namespace ui {
     void getEntryThemeInfo(int* scroll, int* caret, int* state, Range* range) const;
     gfx::Rect getEntryTextBounds() const;
 
+    gfx::PointF scale() const { return m_scale; }
+    void setScale(const gfx::PointF& scale) { m_scale = scale; }
+
     static gfx::Size sizeHintWithText(Entry* entry,
                                       const std::string& text);
 
@@ -70,6 +73,8 @@ namespace ui {
     obs::signal<void()> Change;
 
   protected:
+    gfx::Rect getCharBoxBounds(int charBoxIndex);
+
     // Events
     bool onProcessMessage(Message* msg) override;
     void onSizeHint(SizeHintEvent& ev) override;
@@ -137,6 +142,11 @@ namespace ui {
     bool m_translate_dead_keys : 1;
     Range m_selecting_words;
     std::unique_ptr<std::string> m_suffix;
+
+    // Scale (1.0 by default) applied to each axis. Can be used in
+    // case you are going to display/paint the text scaled and want to
+    // convert the mouse position correctly.
+    gfx::PointF m_scale;
   };
 
 } // namespace ui