fixed #18474: Provides an interface for getting SafeArea (#18489)

* fixed #18474: Provides an interface for getting SafeArea

* Adds getSafeAreaRect test demo in cpp-empty-test.

* @available(iOS 11.0, *) isn't supported in Xcode8. So we use the old way.

cocos/base/CCDirector.cpp

@@ -1,4 +1,4 @@
-/****************************************************************************
+/****************************************************************************
 Copyright (c) 2008-2010 Ricardo Quesada
 Copyright (c) 2010-2013 cocos2d-x.org
 Copyright (c) 2011      Zynga Inc.
@@ -866,6 +866,18 @@ Vec2 Director::getVisibleOrigin() const
     }
 }
 
+Rect Director::getSafeAreaRect() const
+{
+    if (_openGLView)
+    {
+        return _openGLView->getSafeAreaRect();
+    }
+    else
+    {
+        return Rect::ZERO;
+    }
+}
+
 // scene management
 
 void Director::runWithScene(Scene *scene)

cocos/base/CCDirector.h

@@ -256,6 +256,11 @@ public:
     /** Returns visible origin coordinate of the OpenGL view in points. */
     Vec2 getVisibleOrigin() const;
 
+    /**
+     * Returns safe area rectangle of the OpenGL view in points.
+     */
+    Rect getSafeAreaRect() const;
+
     /**
      * Converts a screen coordinate to an OpenGL coordinate.
      * Useful to convert (multi) touch coordinates to the current layout (portrait or landscape).

cocos/platform/CCGLView.cpp

@@ -219,6 +219,11 @@ Rect GLView::getVisibleRect() const
     return ret;
 }
 
+Rect GLView::getSafeAreaRect() const
+{
+    return getVisibleRect();
+}
+
 Size GLView::getVisibleSize() const
 {
     if (_resolutionPolicy == ResolutionPolicy::NO_BORDER)

cocos/platform/CCGLView.h

@@ -239,6 +239,11 @@ public:
      */
     virtual Rect getVisibleRect() const;
 
+    /**
+     * Gets safe area rectangle
+     */
+    virtual Rect getSafeAreaRect() const;
+
     /**
      * Set the design resolution size.
      * @param width Design resolution width.

cocos/platform/ios/CCEAGLView-ios.h

@@ -90,6 +90,7 @@ Copyright (C) 2008 Apple Inc. All Rights Reserved.
     BOOL                    preserveBackbuffer_;
 
     CGSize                  size_;
+    CGRect                  safeArea_;
     BOOL                    discardFramebufferSupported_;
 
     //fsaa addition

cocos/platform/ios/CCGLViewImpl-ios.h

@@ -75,6 +75,8 @@ public:
     virtual void swapBuffers() override;
     virtual void setIMEKeyboardState(bool bOpen) override;
 
+    virtual Rect getSafeAreaRect() const override;
+
 protected:
     GLViewImpl();
     virtual ~GLViewImpl();

cocos/platform/ios/CCGLViewImpl-ios.mm

@@ -32,6 +32,7 @@
 #include "platform/ios/CCDirectorCaller-ios.h"
 #include "platform/ios/CCGLViewImpl-ios.h"
 #include "base/CCTouch.h"
+#include "base/CCDirector.h"
 
 NS_CC_BEGIN
 
@@ -227,6 +228,53 @@ void GLViewImpl::setIMEKeyboardState(bool open)
     }
 }
 
+Rect GLViewImpl::getSafeAreaRect() const
+{
+    CCEAGLView *eaglview = (CCEAGLView*) _eaglview;
+
+#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 110000
+    float version = [[UIDevice currentDevice].systemVersion floatValue];
+    if (version >= 11.0f)
+    {
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wpartial-availability"
+        UIEdgeInsets safeAreaInsets = eaglview.safeAreaInsets;
+#pragma clang diagnostic pop
+
+        // Multiply contentScaleFactor since safeAreaInsets return points.
+        safeAreaInsets.left *= eaglview.contentScaleFactor;
+        safeAreaInsets.right *= eaglview.contentScaleFactor;
+        safeAreaInsets.top *= eaglview.contentScaleFactor;
+        safeAreaInsets.bottom *= eaglview.contentScaleFactor;
+
+        // Get leftBottom and rightTop point in UI coordinates
+        Vec2 leftBottom = Vec2(safeAreaInsets.left, _screenSize.height - safeAreaInsets.bottom);
+        Vec2 rightTop = Vec2(_screenSize.width - safeAreaInsets.right, safeAreaInsets.top);
+
+        // Convert a point from UI coordinates to which in design resolution coordinate.
+        leftBottom.x = (leftBottom.x - _viewPortRect.origin.x) / _scaleX,
+        leftBottom.y = (leftBottom.y - _viewPortRect.origin.y) / _scaleY;
+        rightTop.x = (rightTop.x - _viewPortRect.origin.x) / _scaleX,
+        rightTop.y = (rightTop.y - _viewPortRect.origin.y) / _scaleY;
+
+        // Adjust points to make them inside design resolution
+        leftBottom.x = MAX(leftBottom.x, 0);
+        leftBottom.y = MIN(leftBottom.y, _designResolutionSize.height);
+        rightTop.x = MIN(rightTop.x, _designResolutionSize.width);
+        rightTop.y = MAX(rightTop.y, 0);
+
+        // Convert to GL coordinates
+        leftBottom = Director::getInstance()->convertToGL(leftBottom);
+        rightTop = Director::getInstance()->convertToGL(rightTop);
+
+        return Rect(leftBottom.x, leftBottom.y, rightTop.x - leftBottom.x, rightTop.y - leftBottom.y);
+    }
+#endif
+
+    // If running on iOS devices lower than 11.0, return visiable rect instead.
+    return GLView::getSafeAreaRect();
+}
+
 NS_CC_END
 
 #endif // CC_PLATFORM_IOS

tests/cpp-empty-test/Classes/HelloWorldScene.cpp

@@ -63,6 +63,13 @@ bool HelloWorld::init()
     // add the sprite as a child to this layer
     this->addChild(sprite);
 
+    auto drawNode = DrawNode::create();
+    drawNode->setPosition(Vec2(0, 0));
+    addChild(drawNode);
+
+    Rect safeArea = Director::getInstance()->getSafeAreaRect();
+    drawNode->drawRect(safeArea.origin, safeArea.origin + safeArea.size, Color4F::BLUE);
+
     return true;
 }