Add first implementation of a DisplayRenderingPanel

Makes use of a standard display_writer_t style Lambda so users can use arbitrary APIs from the Display Rendering Engine within the layout engine

esphome/components/graphical_layout/__init__.py

@@ -5,6 +5,7 @@ from esphome.const import CONF_ID
 from . import horizontal_stack
 from . import vertical_stack
 from . import text_panel
+from . import display_rendering_panel
 
 graphical_layout_ns = cg.esphome_ns.namespace("graphical_layout")
 RootLayoutComponent = graphical_layout_ns.class_("RootLayoutComponent", cg.Component)
@@ -68,6 +69,14 @@ ITEM_TYPE_SCHEMA = cv.typed_schema(
                 ),
             }
         ),
+        display_rendering_panel.CONF_TYPE: BASE_ITEM_SCHEMA.extend(
+          {
+              cv.GenerateID(): cv.declare_id(display_rendering_panel.DisplayRenderingPanel),
+              cv.Required(display_rendering_panel.CONF_WIDTH): cv.templatable(cv.int_range(min=1)),
+              cv.Required(display_rendering_panel.CONF_HEIGHT): cv.templatable(cv.int_range(min=1)),
+              cv.Required(display_rendering_panel.CONF_LAMBDA): cv.lambda_,
+          }  
+        ),
     }
 )
 
@@ -75,6 +84,7 @@ CODE_GENERATORS = {
     text_panel.CONF_TYPE: text_panel.config_to_layout_item,
     horizontal_stack.CONF_TYPE: horizontal_stack.config_to_layout_item,
     vertical_stack.CONF_TYPE: vertical_stack.config_to_layout_item,
+    display_rendering_panel.CONF_TYPE: display_rendering_panel.config_to_layout_item,
 }
 
 CONFIG_SCHEMA = cv.Schema(

esphome/components/graphical_layout/display_rendering_panel.cpp

@@ -0,0 +1,26 @@
+#include "display_rendering_panel.h"
+
+#include "esphome/components/display/display.h"
+#include "esphome/components/display/rect.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace graphical_layout {
+
+static const char *const TAG = "displayrenderingpanel";
+
+void DisplayRenderingPanel::dump_config(int indent_depth, int additional_level_depth) {
+  ESP_LOGCONFIG(TAG, "%*sDimensions: %ix%i", indent_depth, "", this->width_, this->height_);
+  ESP_LOGCONFIG(TAG, "%*sHas drawing lambda: %s", indent_depth, "", YESNO(this->lambda_ != nullptr));
+}
+
+const display::Rect DisplayRenderingPanel::measure_item(display::Display *display) {
+  return display::Rect(0, 0, this->width_, this->width_);
+}
+
+void DisplayRenderingPanel::render(display::Display *display, display::Rect bounds) {
+  this->lambda_(*display);
+}
+
+}  // namespace graphical_layout
+}  // namespace esphome

esphome/components/graphical_layout/display_rendering_panel.h

@@ -0,0 +1,32 @@
+#pragma once
+
+#include "esphome/components/graphical_layout/graphical_layout.h"
+#include "esphome/components/font/font.h"
+
+namespace esphome {
+namespace graphical_layout {
+
+/* See display.h for original declaration */
+using display_writer_t = std::function<void(display::Display &)>;
+
+/** The DisplayRenderingPanel is a UI item that renders a custom lambda to the display whilst
+ * participating in the layout process 
+ */
+class DisplayRenderingPanel : public LayoutItem {
+ public:
+  const display::Rect measure_item(display::Display *display);
+  void render(display::Display *display, display::Rect bounds);
+  void dump_config(int indent_depth, int additional_level_depth);
+
+  void set_width(int width) { this->width_ = width; };
+  void set_height(int height) { this->height_ = height; };
+  void set_lambda(display_writer_t lambda) { this->lambda_ = lambda; };
+
+ protected:
+  int width_{0};
+  int height_{0};
+  display_writer_t lambda_{nullptr};
+};
+
+}  // namespace graphical_layout
+}  // namespace esphome

esphome/components/graphical_layout/display_rendering_panel.py

@@ -0,0 +1,27 @@
+import esphome.codegen as cg
+from esphome.const import CONF_ID
+from esphome.components.display import DisplayRef
+
+graphical_layout_ns = cg.esphome_ns.namespace("graphical_layout")
+DisplayRenderingPanel = graphical_layout_ns.class_("DisplayRenderingPanel")
+
+CONF_TYPE = "display_rendering_panel"
+CONF_HEIGHT = "height"
+CONF_WIDTH = "width"
+CONF_LAMBDA = "lambda"
+
+async def config_to_layout_item(item_config, child_item_builder):
+    var = cg.new_Pvariable(item_config[CONF_ID])
+
+    width = await cg.templatable(item_config[CONF_WIDTH], args=[], output_type=int)
+    cg.add(var.set_width(width))
+
+    height = await cg.templatable(item_config[CONF_HEIGHT], args=[], output_type=int)
+    cg.add(var.set_height(height))
+
+    lambda_ = await cg.process_lambda(
+      item_config[CONF_LAMBDA], [(DisplayRef, "it")], return_type=cg.void
+    )
+    cg.add(var.set_lambda(lambda_))
+
+    return var