Add C API for display manager and geometry structs

- Introduce `geometry_c.h` for point, size, and rectangle structs - Add
`display_manager_c.h` and implementation for C API functions: -
`native_display_manager_get_all` - `native_display_manager_get_primary`
- `native_display_manager_get_cursor_position` - Refactor C display API
to use new types and naming conventions - Update example to show usage
of new C API functions

Author: lijy91

examples/display_example/main.cpp

@@ -1,9 +1,10 @@
-#include <iostream>
-#include <iomanip>
-#include <thread>
 #include <chrono>
+#include <iomanip>
+#include <iostream>
 #include <sstream>
+#include <thread>
 #include "nativeapi.h"
+#include "nativeapi_c.h"
 
 using nativeapi::Display;
 using nativeapi::DisplayManager;
@@ -36,26 +37,39 @@ std::string truncateString(const std::string& str, size_t maxLength) {
 
 // Helper function to format a table row with proper alignment
 std::string formatTableRow(const std::string& content, int totalWidth = 70) {
-  std::string truncated = truncateString(content, totalWidth - 4); // Leave space for "│ " and " │"
+  std::string truncated =
+      truncateString(content, totalWidth - 4);  // Leave space for "│ " and " │"
   std::ostringstream oss;
   oss << "│ " << std::left << std::setw(totalWidth - 4) << truncated << " │";
   return oss.str();
 }
 
-// Helper function to create table border - using ASCII characters for better compatibility
-std::string createTableBorder(const std::string& leftChar, const std::string& rightChar, const std::string& fillChar, int width = 70) {
+// Helper function to create table border - using ASCII characters for better
+// compatibility
+std::string createTableBorder(const std::string& leftChar,
+                              const std::string& rightChar,
+                              const std::string& fillChar,
+                              int width = 70) {
   std::string border;
-  if (leftChar == "┌") border = "+";
-  else if (leftChar == "├") border = "+";
-  else if (leftChar == "└") border = "+";
-  else border = leftChar;
+  if (leftChar == "┌")
+    border = "+";
+  else if (leftChar == "├")
+    border = "+";
+  else if (leftChar == "└")
+    border = "+";
+  else
+    border = leftChar;
 
   border += std::string(width - 2, '-');
 
-  if (rightChar == "┐") border += "+";
-  else if (rightChar == "┤") border += "+";
-  else if (rightChar == "┘") border += "+";
-  else border += rightChar;
+  if (rightChar == "┐")
+    border += "+";
+  else if (rightChar == "┤")
+    border += "+";
+  else if (rightChar == "┘")
+    border += "+";
+  else
+    border += rightChar;
 
   return border;
 }
@@ -65,44 +79,54 @@ void printDisplayInfo(const Display& display, bool isPrimary = false) {
   const int tableWidth = 70;
 
   std::cout << createTableBorder("┌", "┐", "─", tableWidth) << std::endl;
-  std::cout << formatTableRow("Display: " + display.name, tableWidth) << std::endl;
+  std::cout << formatTableRow("Display: " + display.name, tableWidth)
+            << std::endl;
   std::cout << createTableBorder("├", "┤", "─", tableWidth) << std::endl;
   std::cout << formatTableRow("ID: " + display.id, tableWidth) << std::endl;
 
   // Format position string
-  std::string positionStr = "Position: (" + std::to_string((int)display.position.x) + ", " + std::to_string((int)display.position.y) + ")";
+  std::string positionStr = "Position: (" +
+                            std::to_string((int)display.position.x) + ", " +
+                            std::to_string((int)display.position.y) + ")";
   std::cout << formatTableRow(positionStr, tableWidth) << std::endl;
 
   // Format size string with proper separator
-  std::string sizeStr = "Size: " + std::to_string((int)display.size.width) + " x " + std::to_string((int)display.size.height);
+  std::string sizeStr = "Size: " + std::to_string((int)display.size.width) +
+                        " x " + std::to_string((int)display.size.height);
   std::cout << formatTableRow(sizeStr, tableWidth) << std::endl;
 
   // Format work area string with proper formatting
-  std::string workAreaStr = "Work Area: (" + std::to_string((int)display.workArea.x) + ", " +
-                           std::to_string((int)display.workArea.y) + ") " +
-                           std::to_string((int)display.workArea.width) + " x " +
-                           std::to_string((int)display.workArea.height);
+  std::string workAreaStr =
+      "Work Area: (" + std::to_string((int)display.workArea.x) + ", " +
+      std::to_string((int)display.workArea.y) + ") " +
+      std::to_string((int)display.workArea.width) + " x " +
+      std::to_string((int)display.workArea.height);
   std::cout << formatTableRow(workAreaStr, tableWidth) << std::endl;
 
   // Format scale factor string
   std::stringstream scaleStream;
-  scaleStream << "Scale Factor: " << std::fixed << std::setprecision(2) << display.scaleFactor;
+  scaleStream << "Scale Factor: " << std::fixed << std::setprecision(2)
+              << display.scaleFactor;
   std::cout << formatTableRow(scaleStream.str(), tableWidth) << std::endl;
 
   // Format primary status
-  std::string primaryStr = "Primary: " + std::string(display.isPrimary ? "Yes" : "No");
+  std::string primaryStr =
+      "Primary: " + std::string(display.isPrimary ? "Yes" : "No");
   std::cout << formatTableRow(primaryStr, tableWidth) << std::endl;
 
   // Format orientation
-  std::string orientationStr = "Orientation: " + orientationToString(display.orientation);
+  std::string orientationStr =
+      "Orientation: " + orientationToString(display.orientation);
   std::cout << formatTableRow(orientationStr, tableWidth) << std::endl;
 
   // Format refresh rate
-  std::string refreshStr = "Refresh Rate: " + std::to_string(display.refreshRate) + " Hz";
+  std::string refreshStr =
+      "Refresh Rate: " + std::to_string(display.refreshRate) + " Hz";
   std::cout << formatTableRow(refreshStr, tableWidth) << std::endl;
 
   if (display.bitDepth > 0) {
-    std::string bitDepthStr = "Bit Depth: " + std::to_string(display.bitDepth) + " bits";
+    std::string bitDepthStr =
+        "Bit Depth: " + std::to_string(display.bitDepth) + " bits";
     std::cout << formatTableRow(bitDepthStr, tableWidth) << std::endl;
   }
 
@@ -156,7 +180,8 @@ int main() {
 
     // Display cursor position
     Point cursorPos = displayManager.GetCursorPosition();
-    std::cout << "🖱️  Current Cursor Position: (" << cursorPos.x << ", " << cursorPos.y << ")" << std::endl;
+    std::cout << "🖱️  Current Cursor Position: (" << cursorPos.x << ", "
+              << cursorPos.y << ")" << std::endl;
     std::cout << std::endl;
 
     // Display summary statistics
@@ -176,13 +201,16 @@ int main() {
     std::cout << createTableBorder("┌", "┐", "─", summaryWidth) << std::endl;
 
     // Format each summary line properly
-    std::string totalDisplaysStr = "Total Displays: " + std::to_string(displays.size());
+    std::string totalDisplaysStr =
+        "Total Displays: " + std::to_string(displays.size());
     std::cout << formatTableRow(totalDisplaysStr, summaryWidth) << std::endl;
 
-    std::string combinedWidthStr = "Combined Width: " + std::to_string((int)totalWidth);
+    std::string combinedWidthStr =
+        "Combined Width: " + std::to_string((int)totalWidth);
     std::cout << formatTableRow(combinedWidthStr, summaryWidth) << std::endl;
 
-    std::string maxHeightStr = "Max Height: " + std::to_string((int)totalHeight);
+    std::string maxHeightStr =
+        "Max Height: " + std::to_string((int)totalHeight);
     std::cout << formatTableRow(maxHeightStr, summaryWidth) << std::endl;
 
     std::stringstream scaleRangeStream;
@@ -202,5 +230,15 @@ int main() {
   }
 
   std::cout << "\n✅ Display information retrieved successfully!" << std::endl;
+
+  native_display_list_t display_list = native_display_manager_get_all();
+
+  std::cout << "C API - Found " << display_list.count
+            << " display(s):" << std::endl;
+  for (size_t i = 0; i < display_list.count; ++i) {
+    std::cout << "Display " << (i + 1)
+              << " Name: " << display_list.displays[i].name << std::endl;
+  }
+
   return 0;
-}
+}

include/nativeapi_c.h

@@ -1,3 +1,5 @@
 #pragma once
 
 #include "../src/capi/display_c.h"
+#include "../src/capi/display_manager_c.h"
+#include "../src/capi/geometry_c.h"