mouse_middle_button_grab

drag canvas when using processon

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         mouse_middle_button_grab
// @namespace    
// @version      0.3
// @description  drag canvas when using processon
// @author       SimonTheCoder
// @match        https://www.processon.com/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    console.log("mouse_middle_button_grab loaded.");
    var diaType = "diagram";
    var designer_layout = document.getElementById("designer_layout");
    if(!designer_layout){
        console.log("seems we are drawing mindmap.");
        designer_layout = document.getElementById("canvas_container");
        diaType = "mindmap";
    }

    //var designer_layout = document.getElementById("canvas_container");
    console.log("designer_layout:"+designer_layout);

    var sampleStartX = 0;
    var sampleStartY = 0;
    var startTimeStamp = 0;
    var lastX = 0;
    var lastY = 0;
    var global_test_e = null;
    var middle_down = false;
    designer_layout.onmousedown = function(e) {
        if(e.button == 1){
            global_test_e = e;
            lastX = e.x;
            lastY = e.y;

            sampleStartX = e.x;
            sampleStartY = e.x;
            startTimeStamp = e.timeStamp;

            //console.log("middle mouse down. x =" + e.x + " y=" +e.y);
            middle_down = true;
            //e.stopPropagation();
        }
    };
    designer_layout.onmouseup = function(e){
        if(e.button == 1){
            global_test_e = e;
            //console.log("middle mouse up. x =" + e.x + " y=" +e.y);
            //console.log("middle mouse up. lastx =" + lastX + " lastY=" +lastY);
            //console.log("middle mouse up. time=" + (e.timeStamp - startTimeStamp));
            var endSpeed = Math.sqrt((e.x-sampleStartX)*(e.x-sampleStartX) + (e.y-sampleStartY)*(e.y-sampleStartY))/(e.timeStamp - startTimeStamp);
            //console.log("middle mouse up. lastSpeed= " + endSpeed);
            lastX = e.x;
            lastY = e.y;

            middle_down = false;
            //e.stopPropagation();
        }
    };
    designer_layout.onmousemove = function(e){
        //console.log("mouse move button=%d", e.button);
        if(middle_down === true){
            //console.log("middle mouse move. x =" + e.x + " y=" +e.y + " lastx =" + lastX + " lasty=" +lastY );
            designer_layout.scrollTop = designer_layout.scrollTop - (e.y - lastY);
            designer_layout.scrollLeft = designer_layout.scrollLeft - (e.x - lastX);
            lastX = e.x;
            lastY = e.y;

            if(e.timestamp - startTimeStamp > 200){
                sampleStartX = e.x;
                sampleStartY = e.x;
                startTimeStamp = e.timeStamp;
            }
            //e.stopPropagation();
        }

    };
    designer_layout.onmousewheel = function(e){
        if(e.altKey === true && e.shiftKey === true){
            //console.log("zoom: " + e.deltaY);
            var oldScale = Designer.config.scale;
            var oldScrollTop = designer_layout.scrollTop;
            var oldScrollLeft = designer_layout.scrollLeft;
            var oldScrollWidth = designer_layout.scrollWidth;
            var oldScrollHeight = designer_layout.scrollHeight;
            if(e.deltaY > 0){
                if(diaType == "mindmap"){
                    document.getElementById("btn_zoomsmall").click();
                }else{
                    Designer.zoomOut();
                }
            }else{
                if(diaType == "mindmap"){
                    document.getElementById("btn_zoombig").click();
                }else{

                    if(Designer.config.scale < 0.3){
                        Designer.setZoomScale(0.4);
                    }else{
                        Designer.zoomIn();
                    }
                }
            }
            var newScale = Designer.config.scale;

            //console.log(e);
            recalcScrollAfterScaleChanged(oldScrollTop,oldScrollLeft,oldScrollWidth,oldScrollHeight,oldScale,newScale,e.x,e.y);
            e.preventDefault();
            e.stopPropagation();
        }

    };

    if(diaType == "diagram"){
        designer_layout.ondblclick = function(e){
            if(e.button==1){
                var oldScale = Designer.config.scale;
                var oldScrollTop = designer_layout.scrollTop;
                var oldScrollLeft = designer_layout.scrollLeft;
                var oldScrollWidth = designer_layout.scrollWidth;
                var oldScrollHeight = designer_layout.scrollHeight;

                console.log("clear set zoom scale to 1.");
                Designer.setZoomScale(1);
                recalcScrollAfterScaleChanged(oldScrollTop,oldScrollLeft,oldScrollWidth,oldScrollHeight,oldScale,1.0,e.x,e.y);

            }
        };
    }
    function recalcScrollAfterScaleChanged(oldScrollTop,oldScrollLeft,oldScrollWidth,oldScrollHeight,oldScale, newScale, centerX, centerY){
        if(diaType != "diagram") return; //supports diagram only
        console.log("top,left= " +designer_layout.scrollTop +" ,"+designer_layout.scrollLeft+" scale:"+ oldScale + ","+newScale);
        var diaClientRect = designer_layout.getClientRects()[0];
        var offsetTop = centerY - diaClientRect.top;
        var offsetLeft = centerX - diaClientRect.left;
        console.log("offset:"+offsetTop + ","+offsetLeft);

        var centerPointScrollTopOrigFactor = (oldScrollTop + offsetTop)/oldScrollHeight;
        var centerPointScrollLeftOrigFactor = (oldScrollLeft + offsetLeft)/oldScrollWidth;
        var centerPointScrollTopNew = centerPointScrollTopOrigFactor * designer_layout.scrollHeight;
        var centerPointScrollLeftNew = centerPointScrollLeftOrigFactor * designer_layout.scrollWidth;
        designer_layout.scrollTop = centerPointScrollTopNew - offsetTop;
        designer_layout.scrollLeft = centerPointScrollLeftNew - offsetLeft;

/*
        designer_layout.scrollTop = designer_layout.scrollHeight * (oldScrollTop + offsetTop)/oldScrollHeight  - offsetTop;
        designer_layout.scrollLeft =designer_layout.scrollWidth * (oldScrollLeft + offsetLeft)/oldScrollWidth  - offsetLeft;
*/
    }
    /*
    function recalcScrollAfterScaleChanged(oldScale, newScale){
        if(diaType != "diagram") return; //supports diagram only
        var diaClientRect = designer_layout.getClientRects()[0];
        var centerPointScrollTopOrig = (designer_layout.scrollTop + diaClientRect.height/2)/oldScale;
        var centerPointScrollLeftOrig = (designer_layout.scrollLeft + diaClientRect.width/2)/oldScale;
        var centerPointScrollTopNew = centerPointScrollTopOrig * newScale;
        var centerPointScrollLeftNew = centerPointScrollLeftOrig * newScale;
        designer_layout.scrollTop = centerPointScrollTopNew - diaClientRect.height/2/oldScale*newScale;
        designer_layout.scrollLeft = centerPointScrollLeftNew - diaClientRect.width/2/oldScale*newScale;
    }*/
    /*
    designer_layout.onclick = function(e){
        if(e.button == 1){
            e.stopPropagation();
        }
    };
    */
})();


(function() {
    'use strict';

    // Your code here...
})();