UIPanGestureRecognizer impl

XITRIX · Dec 17, 2024 · 85f2733 · 85f2733
1 parent 8d104df
commit 85f2733
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diff --git a/Submodules/UIKit/CMakeLists.txt b/Submodules/UIKit/CMakeLists.txt
@@ -33,6 +33,7 @@ add_library(UIKit
         lib/UIImageView.cpp
         lib/UIKey.cpp
         lib/UILabel.cpp
+        lib/UIPanGestureRecognizer.cpp
         lib/UIPress.cpp
         lib/UIPressesEvent.cpp
         lib/UIResponder.cpp

diff --git a/Submodules/UIKit/include/UIKit.h b/Submodules/UIKit/include/UIKit.h
@@ -10,3 +10,4 @@
 #include <UILabel.h>
 #include <UIViewController.h>
 #include <UITapGestureRecognizer.h>
+#include <UIPanGestureRecognizer.h>
diff --git a/Submodules/UIKit/include/UIPanGestureRecognizer.h b/Submodules/UIKit/include/UIPanGestureRecognizer.h
@@ -0,0 +1,29 @@
+#pragma once
+
+#include <UIGestureRecognizer.h>
+#include <Timer.h>
+#include <Geometry.h>
+
+namespace NXKit {
+
+class UIPanGestureRecognizer: public UIGestureRecognizer {
+public:
+    void touchesBegan(std::vector<std::shared_ptr<UITouch>> touches, std::shared_ptr<UIEvent> event) override;
+    void touchesMoved(std::vector<std::shared_ptr<UITouch>> touches, std::shared_ptr<UIEvent> event) override;
+    void touchesEnded(std::vector<std::shared_ptr<UITouch>> touches, std::shared_ptr<UIEvent> event) override;
+
+    NXPoint translationInView(std::shared_ptr<UIView> view);
+    void setTranslation(NXPoint translation, std::shared_ptr<UIView> inView);
+
+    NXPoint velocityIn(std::shared_ptr<UIView> view);
+
+private:
+    std::shared_ptr<UITouch> trackingTouch;
+    NXPoint initialTouchPoint;
+    Timer touchesMovedTimestamp;
+    Timer previousTouchesMovedTimestamp;
+
+    NXPoint velocityIn(std::shared_ptr<UIView> view, float timeDiffSeconds);
+};
+
+}
diff --git a/Submodules/UIKit/lib/UIPanGestureRecognizer.cpp b/Submodules/UIKit/lib/UIPanGestureRecognizer.cpp
@@ -0,0 +1,85 @@
+#include <UIPanGestureRecognizer.h>
+#include <UITouch.h>
+#include <UIWindow.h>
+
+namespace NXKit {
+
+#define THRESHOLD 10
+
+NXPoint UIPanGestureRecognizer::translationInView(std::shared_ptr<UIView> view) {
+    if (!trackingTouch) return NXPoint();
+
+    auto positionInTargetView = trackingTouch->locationIn(view);
+    NXPoint initialPositionInTargetView;
+    if (trackingTouch->window().expired()) initialPositionInTargetView = initialTouchPoint;
+    else { initialPositionInTargetView = view ? trackingTouch->window().lock()->convertToView(initialTouchPoint, view) : initialTouchPoint; }
+
+    return positionInTargetView - initialPositionInTargetView;
+}
+
+void UIPanGestureRecognizer::setTranslation(NXPoint translation, std::shared_ptr<UIView> inView) {
+    if (!trackingTouch) return;
+
+    auto positionInTargetView = trackingTouch->locationIn(nullptr);
+    initialTouchPoint = positionInTargetView - translation;
+}
+
+NXPoint UIPanGestureRecognizer::velocityIn(std::shared_ptr<UIView> view, float timeDiffSeconds) {
+    if (!trackingTouch || timeDiffSeconds == 0) return NXPoint();
+
+    NXPoint curPos = trackingTouch->locationIn(view);
+    NXPoint prevPos = trackingTouch->previousLocationIn(view);
+
+    return (curPos - prevPos) / (float)timeDiffSeconds;
+}
+
+NXPoint UIPanGestureRecognizer::velocityIn(std::shared_ptr<UIView> view) {
+    float timeDiffSeconds = touchesMovedTimestamp - previousTouchesMovedTimestamp;
+    timeDiffSeconds /= 100000.0f;
+    return velocityIn(view, timeDiffSeconds);
+}
+
+void UIPanGestureRecognizer::touchesBegan(std::vector<std::shared_ptr<UITouch>> touches, std::shared_ptr<UIEvent> event) {
+    UIGestureRecognizer::touchesBegan(touches, event);
+    if (!trackingTouch) {
+        trackingTouch = touches[0];
+        initialTouchPoint = trackingTouch->locationIn(nullptr);
+        touchesMovedTimestamp = trackingTouch->timestamp();
+        previousTouchesMovedTimestamp = trackingTouch->timestamp();
+        onStateChanged(UIGestureRecognizerState::possible);
+    }
+}
+
+void UIPanGestureRecognizer::touchesMoved(std::vector<std::shared_ptr<UITouch>> touches, std::shared_ptr<UIEvent> event) {
+    UIGestureRecognizer::touchesMoved(touches, event);
+    if (trackingTouch == touches[0]) {
+        if (state() == UIGestureRecognizerState::possible) {
+            NXPoint diff = initialTouchPoint - trackingTouch->locationIn(nullptr);
+//            printf("x %f, y %f\n", diff.x, diff.y);
+            if (abs(diff.x) >= THRESHOLD || abs(diff.y) >= THRESHOLD) {
+                // Reset initial touch point to remove "jiggle" effect after start of recognition
+                initialTouchPoint = trackingTouch->locationIn(nullptr);
+                touchesMovedTimestamp = trackingTouch->timestamp();
+                previousTouchesMovedTimestamp = trackingTouch->timestamp();
+                setState(UIGestureRecognizerState::began);
+                setState(UIGestureRecognizerState::changed);
+            }
+        } else if (state() == UIGestureRecognizerState::changed) {
+            previousTouchesMovedTimestamp = touchesMovedTimestamp;
+            touchesMovedTimestamp = trackingTouch->timestamp();
+            onStateChanged(UIGestureRecognizerState::changed);
+        }
+    }
+}
+
+void UIPanGestureRecognizer::touchesEnded(std::vector<std::shared_ptr<UITouch>> touches, std::shared_ptr<UIEvent> event) {
+    UIGestureRecognizer::touchesEnded(touches, event);
+    if (trackingTouch == touches[0]) {
+        previousTouchesMovedTimestamp = touchesMovedTimestamp;
+        touchesMovedTimestamp = trackingTouch->timestamp();
+        setState(UIGestureRecognizerState::ended);
+        trackingTouch = nullptr;
+    }
+}
+
+}
diff --git a/app/Screens/TestViewController/TestViewController.cpp b/app/Screens/TestViewController/TestViewController.cpp
@@ -148,6 +148,38 @@ void TestViewController::loadView() {
     };
     button->addGestureRecognizer(tapGesture);
 
+    auto dragMeView = new_shared<UILabel>();
+    dragMeView->setText("Drag me!");
+    dragMeView->setFontWeight(600);
+    dragMeView->setTextAlignment(NSTextAlignment::center);
+    dragMeView->setFrame({ 100, 400, 200, 200 });
+    dragMeView->layer()->setCornerRadius(12);
+    dragMeView->setBackgroundColor(UIColor::orange);
+    rootView->addSubview(dragMeView);
+
+    auto panGesture = new_shared<UIPanGestureRecognizer>();
+    panGesture->onStateChanged = [this, dragMeView, panGesture](UIGestureRecognizerState status) {
+        static NXPoint initial;
+        switch (status) {
+            case UIGestureRecognizerState::began: {
+                initial = dragMeView->frame().origin;
+                break;
+            }
+            case UIGestureRecognizerState::changed: {
+                auto translation = panGesture->translationInView(view());
+
+                auto frame = dragMeView->frame();
+                frame.origin.x = initial.x + translation.x;
+                frame.origin.y = initial.y + translation.y;
+                dragMeView->setFrame(frame);
+                break;
+            }
+            default:
+                break;
+        }
+    };
+    dragMeView->addGestureRecognizer(panGesture);
+
     setView(rootView);
 }