Merge branch 'master' of github.com:vjeux/excalibur

.gitignore

@@ -7,3 +7,4 @@ yarn-error.log*
 
 # Dependency directories
 node_modules/
+.vscode/

src/index.tsx

@@ -10,20 +10,99 @@ export type ExcaliburTextElement = ExcaliburElement & {
   type: "text";
   font: string;
   text: string;
-  measure: TextMetrics;
+  actualBoundingBoxAscent: number;
 };
 
 // var elements = Array.of<ExcaliburElement>();
 
-function isInsideAnElement(x: number, y: number) {
-  return (element: ExcaliburElement) => {
+// https://stackoverflow.com/a/6853926/232122
+function distanceBetweenPointAndSegment(
+  x: number,
+  y: number,
+  x1: number,
+  y1: number,
+  x2: number,
+  y2: number
+) {
+  const A = x - x1;
+  const B = y - y1;
+  const C = x2 - x1;
+  const D = y2 - y1;
+
+  const dot = A * C + B * D;
+  const lenSquare = C * C + D * D;
+  let param = -1;
+  if (lenSquare !== 0) {
+    // in case of 0 length line
+    param = dot / lenSquare;
+  }
+
+  let xx, yy;
+  if (param < 0) {
+    xx = x1;
+    yy = y1;
+  } else if (param > 1) {
+    xx = x2;
+    yy = y2;
+  } else {
+    xx = x1 + param * C;
+    yy = y1 + param * D;
+  }
+
+  const dx = x - xx;
+  const dy = y - yy;
+  return Math.sqrt(dx * dx + dy * dy);
+}
+
+function hitTest(element: ExcaliburElement, x: number, y: number): boolean {
+  // For shapes that are composed of lines, we only enable point-selection when the distance
+  // of the click is less than x pixels of any of the lines that the shape is composed of
+  const lineThreshold = 10;
+
+  if (
+    element.type === "rectangle" ||
+    // There doesn't seem to be a closed form solution for the distance between
+    // a point and an ellipse, let's assume it's a rectangle for now...
+    element.type === "ellipse"
+  ) {
+    const x1 = getElementAbsoluteX1(element);
+    const x2 = getElementAbsoluteX2(element);
+    const y1 = getElementAbsoluteY1(element);
+    const y2 = getElementAbsoluteY2(element);
+
+    // (x1, y1) --A-- (x2, y1)
+    //    |D             |B
+    // (x1, y2) --C-- (x2, y2)
+    return (
+      distanceBetweenPointAndSegment(x, y, x1, y1, x2, y1) < lineThreshold || // A
+      distanceBetweenPointAndSegment(x, y, x2, y1, x2, y2) < lineThreshold || // B
+      distanceBetweenPointAndSegment(x, y, x2, y2, x1, y2) < lineThreshold || // C
+      distanceBetweenPointAndSegment(x, y, x1, y2, x1, y1) < lineThreshold // D
+    );
+  } else if (element.type === "arrow") {
+    let [x1, y1, x2, y2, x3, y3, x4, y4] = getArrowPoints(element);
+    // The computation is done at the origin, we need to add a translation
+    x -= element.x;
+    y -= element.y;
+
+    return (
+      //    \
+      distanceBetweenPointAndSegment(x, y, x3, y3, x2, y2) < lineThreshold ||
+      // -----
+      distanceBetweenPointAndSegment(x, y, x1, y1, x2, y2) < lineThreshold ||
+      //    /
+      distanceBetweenPointAndSegment(x, y, x4, y4, x2, y2) < lineThreshold
+    );
+  } else if (element.type === "text") {
     const x1 = getElementAbsoluteX1(element);
     const x2 = getElementAbsoluteX2(element);
     const y1 = getElementAbsoluteY1(element);
     const y2 = getElementAbsoluteY2(element);
 
     return x >= x1 && x <= x2 && y >= y1 && y <= y2;
-  };
+  } else {
+    throw new Error("Unimplemented type " + element.type);
+  }
 }
 
 function newElement(type: string, x: number, y: number, width = 0, height = 0) {
@@ -59,6 +138,26 @@ function isTextElement(
   return element.type === "text";
 }
 
+function getArrowPoints(element: ExcaliburElement) {
+  const x1 = 0;
+  const y1 = 0;
+  const x2 = element.width;
+  const y2 = element.height;
+
+  const size = 30; // pixels
+  const distance = Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2));
+  // Scale down the arrow until we hit a certain size so that it doesn't look weird
+  const minSize = Math.min(size, distance / 2);
+  const xs = x2 - ((x2 - x1) / distance) * minSize;
+  const ys = y2 - ((y2 - y1) / distance) * minSize;
+
+  const angle = 20; // degrees
+  const [x3, y3] = rotate(xs, ys, x2, y2, (-angle * Math.PI) / 180);
+  const [x4, y4] = rotate(xs, ys, x2, y2, (angle * Math.PI) / 180);
+
+  return [x1, y1, x2, y2, x3, y3, x4, y4];
+}
+
 function generateDraw(element: ExcaliburElement) {
   if (element.type === "selection") {
     element.draw = (rc, context) => {
@@ -87,22 +186,7 @@ function generateDraw(element: ExcaliburElement) {
       context.translate(-element.x, -element.y);
     };
   } else if (element.type === "arrow") {
-    const x1 = 0;
-    const y1 = 0;
-    const x2 = element.width;
-    const y2 = element.height;
-
-    const size = 30; // pixels
-    const distance = Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2));
-    // Scale down the arrow until we hit a certain size so that it doesn't look weird
-    const minSize = Math.min(size, distance / 2);
-    const xs = x2 - ((x2 - x1) / distance) * minSize;
-    const ys = y2 - ((y2 - y1) / distance) * minSize;
-
-    const angle = 20; // degrees
-    const [x3, y3] = rotate(xs, ys, x2, y2, (-angle * Math.PI) / 180);
-    const [x4, y4] = rotate(xs, ys, x2, y2, (angle * Math.PI) / 180);
-
+    const [x1, y1, x2, y2, x3, y3, x4, y4] = getArrowPoints(element);
     const shapes = [
       //    \
       generator.line(x3, y3, x2, y2),
@@ -125,7 +209,7 @@ function generateDraw(element: ExcaliburElement) {
       context.fillText(
         element.text,
         element.x,
-        element.y + element.measure.actualBoundingBoxAscent
+        element.y + element.actualBoundingBoxAscent
       );
       context.font = font;
     };
@@ -208,17 +292,20 @@ class App extends React.Component<{}, AppState> {
     this.setState({ elements: newElements });
   };
 
+  deleteSelectedElements = () => {
+    this.setState({ elements: this.state.elements.filter(e => !e.isSelected) });
+  };
+
   private onKeyDown = (event: KeyboardEvent) => {
-    const { elements } = this.state;
-    if (
-      event.key === "Backspace" &&
-      (event.target as HTMLElement)?.nodeName !== "INPUT"
-    ) {
-      for (var i = elements.length - 1; i >= 0; --i) {
-        if (elements[i].isSelected) {
-          elements.splice(i, 1);
-        }
-      }
+    if ((event.target as HTMLElement).nodeName === "INPUT") {
+      return;
+    }
+
+    if (event.key === "Escape") {
+      this.clearSelection();
+      drawScene(this.state.elements);
+    } else if (event.key === "Backspace") {
+      this.deleteSelectedElements();
       drawScene(this.state.elements);
       event.preventDefault();
     } else if (
@@ -228,7 +315,7 @@ class App extends React.Component<{}, AppState> {
       event.key === "ArrowDown"
     ) {
       const step = event.shiftKey ? 5 : 1;
-      elements.forEach(element => {
+      this.state.elements.forEach(element => {
         if (element.isSelected) {
           if (event.key === "ArrowLeft") element.x -= step;
           else if (event.key === "ArrowRight") element.x += step;
@@ -392,7 +479,55 @@ class App extends React.Component<{}, AppState> {
           />
           px)
         </div>
-        <div>
+        <div
+          onCut={e => {
+            e.clipboardData.setData(
+              "text/plain",
+              JSON.stringify(
+                this.state.elements.filter(element => element.isSelected)
+              )
+            );
+            this.deleteSelectedElements();
+            drawScene(this.state.elements);
+            e.preventDefault();
+          }}
+          onCopy={e => {
+            e.clipboardData.setData(
+              "text/plain",
+              JSON.stringify(
+                this.state.elements.filter(element => element.isSelected)
+              )
+            );
+            e.preventDefault();
+          }}
+          onPaste={e => {
+            const paste = e.clipboardData.getData("text");
+            console.log(paste);
+            let parsedElements;
+            try {
+              parsedElements = JSON.parse(paste);
+            } catch (e) {}
+            if (
+              Array.isArray(parsedElements) &&
+              parsedElements.length > 0 &&
+              parsedElements[0].type // need to implement a better check here...
+            ) {
+              this.clearSelection();
+
+              parsedElements = parsedElements.map(parsedElement => {
+                parsedElement.x += 10;
+                parsedElement.y += 10;
+                generateDraw(parsedElement);
+                return parsedElement;
+              });
+              this.setState({
+                elements: [...this.state.elements, ...parsedElements]
+              });
+              drawScene(this.state.elements);
+            }
+            e.preventDefault();
+          }}
+        >
           {this.renderOption({ type: "rectangle", children: "Rectangle" })}
           {this.renderOption({ type: "ellipse", children: "Ellipse" })}
           {this.renderOption({ type: "arrow", children: "Arrow" })}
@@ -409,16 +544,23 @@ class App extends React.Component<{}, AppState> {
               let isDraggingElements = false;
               const cursorStyle = document.documentElement.style.cursor;
               if (this.state.elementType === "selection") {
-                const selectedElement = this.state.elements.find(element => {
-                  const isSelected = isInsideAnElement(x, y)(element);
-                  if (isSelected) {
-                    element.isSelected = true;
-                  }
-                  return isSelected;
+                const hitElement = this.state.elements.find(element => {
+                  return hitTest(element, x, y);
                 });
 
-                if (selectedElement) {
-                  this.setState({ draggingElement: selectedElement });
+                // If we click on something
+                if (hitElement) {
+                  if (hitElement.isSelected) {
+                    // If that element is not already selected, do nothing,
+                    // we're likely going to drag it
+                  } else {
+                    // We unselect every other elements unless shift is pressed
+                    if (!e.shiftKey) {
+                      this.clearSelection();
+                    }
+                    // No matter what, we select it
+                    hitElement.isSelected = true;
+                  }
                 } else {
                   this.clearSelection();
                 }
@@ -441,15 +583,19 @@ class App extends React.Component<{}, AppState> {
                 element.font = "20px Virgil";
                 const font = context.font;
                 context.font = element.font;
-                element.measure = context.measureText(element.text);
+                const {
+                  actualBoundingBoxAscent,
+                  actualBoundingBoxDescent,
+                  width
+                } = context.measureText(element.text);
+                element.actualBoundingBoxAscent = actualBoundingBoxAscent;
                 context.font = font;
                 const height =
-                  element.measure.actualBoundingBoxAscent +
-                  element.measure.actualBoundingBoxDescent;
+                  actualBoundingBoxAscent + actualBoundingBoxDescent;
                 // Center the text
-                element.x -= element.measure.width / 2;
-                element.y -= element.measure.actualBoundingBoxAscent;
-                element.width = element.measure.width;
+                element.x -= width / 2;
+                element.y -= actualBoundingBoxAscent;
+                element.width = width;
                 element.height = height;
               }