Creating replacement for leaderline

2023-07-15 22:00:27 +02:00 · 2023-07-15 22:00:27 +02:00 · a3251f2fdd
commit a3251f2fdd
parent 340b0eef6b
1 changed files with 143 additions and 0 deletions
--- a/amd/src/simpleline.js
+++ b/amd/src/simpleline.js
@ -0,0 +1,143 @@
+/*eslint no-console: "off"*/
+
+/**
+ * Copies defined properties in to, over from the from object. Does so recursively
+ * Ysed to copy user defined parameters onto a pre-existing object with defaults preset.
+ * @param {Object} to The object to copy to
+ * @param {Object} from The object tp copy from (but only the properties already named in "to")
+ */
+const specsCopy = (to, from) => {
+    for(const ix in to){
+        if(from.hasOwnProperty(ix)){
+            if( typeof to[ix] == "object"
+                && typeof from[ix] == "object")
+            {
+                if(Array.isArray(to[ix])){
+                    if(Array.isArray(from[ix])){
+                        to[ix] = Array.from(from[ix]);
+                    } // else, skip...
+                } else {
+                    specsCopy(to[ix], from[ix]); // recursive copy
+                }
+            }
+            else {
+                to[ix] = from[ix];
+            }
+        }
+    }
+};
+
+/**
+ * Check if an element is a containing element and can thus be a parent for absolute positioning
+ * Which is the cas if the element has
+ *  1 A position value other than static (fixed, absolute, relative, or sticky).
+ *  2 A transform or perspective value other than none
+ *  3 A will-change value of transform or perspective
+ *  4 A filter value other than none or a will-change value of filter (only works on Firefox)
+ *  5 A contain value of layout, paint, strict or content (e.g. contain: paint;)
+ *  6 A container-type value other than normal
+ *  7 A backdrop-filter other than none (e.g. backdrop-filter: blur(10px);)
+ * @param {HTMLElement} el
+ * @returns {Boolean}
+ */
+const isContainingElement = (el) => {
+    const cssStyle = getComputedStyle(el);
+    return      ["fixed","absolute","relative","sticky",].includes(cssStyle.position)
+            ||  cssStyle.transform !== "none"
+            ||  cssStyle.perspective !== "none"
+            ||  ["transform","perspective"].includes(cssStyle.willChange)
+            ||  cssStyle.filter !== "none"
+            ||  cssStyle.contain == "paint"
+            ||  cssStyle.backdropFilter !== "none";
+};
+
+export class SimpleLine {
+
+    constructor(start, end, specs){
+        this.svg = null;
+
+        // setup defaults
+        this.specs = {
+            container: null,
+            class: "",
+            colors: {
+                line : "currentcolor",
+                arrow: "currentcolor",
+            },
+            anchors: {
+                // top, middle, bottom
+                // left, center, right
+                start: ["middle","right"],
+                end: ["middle", "left"],
+            }
+        };
+
+        specsCopy(this.specs,specs);
+
+        // Validate start element
+        if(start instanceof HTMLElement) {
+            this.start = start;
+        } else if (typeof this.start === 'string' || this.start instanceof String) {
+            this.startSelector = start;
+            this.start = document.querySelector(start);
+            if(!(this.start instanceof HTMLElement)){
+                console.error("Cannot find start element:",start);
+                return;
+            }
+        } else {
+            console.error("Start element not string or dom element",start);
+        }
+
+        // Validate end element
+        if(end instanceof HTMLElement) {
+            this.end = end;
+        } else if (typeof this.end === 'string' || this.end instanceof String) {
+            this.endSelector = end;
+            this.end = document.querySelector(end);
+            if(!(this.end instanceof HTMLElement)){
+                console.error("Cannot find end element:",end);
+                return;
+            }
+        } else {
+            console.error("End element not string or dom element",start);
+        }
+
+        // Validate or determine container
+        if(this.specs.container){
+            if(this.specs.container instanceof HTMLElement){
+                this.container = this.specs.container;
+            }
+            else if (typeof this.specs.container === 'string' || this.specs.container instanceof String) {
+                this.container = document.querySelector(this.specs.container);
+                if(!(this.container instanceof HTMLElement)){
+                    console.warn("Cannot find specified container element:",this.specs.container);
+                    this.specs.container = null;
+                }
+            }
+            else {
+                console.warn("Container specified is not a string or element:",this.specs.container);
+                this.specs.container = null;
+            }
+        }
+        if(!this.specs.container) { // if originally empty, or cleared
+            // find the first parent element of start that has position css attribute set (or body if none has it set)
+            const body = document.querySelector("body");
+            let el = this.start.parentElement;
+            while( el !== body && !isContainingElement(el)){
+                el = el.parentElement;
+            }
+            this.container = el;
+        }
+
+
+    }
+
+    paintSvg(){
+        const svg = document.createElement("svg");
+        svg.attributes["viewBox"] = "";
+        svg.attributes["width"] = "";
+        svg.attributes["height"] = "";
+    }
+
+
+}