From a185ae4e15627f8901aef89d0eb4ce58205499ac Mon Sep 17 00:00:00 2001
From: Filip Barl <filip.barl@gmail.com>
Date: Tue, 15 Aug 2017 16:41:12 +0200
Subject: [PATCH] Introduced hand cursor and unified ZoomableCanvas usage.

---
 client/app/scripts/charts/nodes-chart.js      | 16 +++-
 .../app/scripts/components/nodes-resources.js |  2 +-
 .../app/scripts/components/zoomable-canvas.js | 75 ++++++++-----------
 client/app/styles/_base.scss                  |  9 +++
 4 files changed, 55 insertions(+), 47 deletions(-)

diff --git a/client/app/scripts/charts/nodes-chart.js b/client/app/scripts/charts/nodes-chart.js
index e200efe1f..fcbc60a8d 100644
--- a/client/app/scripts/charts/nodes-chart.js
+++ b/client/app/scripts/charts/nodes-chart.js
@@ -3,6 +3,7 @@ import { connect } from 'react-redux';
 
 import NodesChartElements from './nodes-chart-elements';
 import ZoomableCanvas from '../components/zoomable-canvas';
+import { transformToString } from '../utils/transform-utils';
 import { clickBackground } from '../actions/app-actions';
 import {
   graphZoomLimitsSelector,
@@ -43,17 +44,24 @@ class NodesChart extends React.Component {
     }
   }
 
+  renderContent(transform) {
+    return (
+      <g transform={transformToString(transform)}>
+        <EdgeMarkerDefinition selectedNodeId={this.props.selectedNodeId} />
+        <NodesChartElements />
+      </g>
+    );
+  }
+
   render() {
-    const { selectedNodeId } = this.props;
     return (
       <div className="nodes-chart">
         <ZoomableCanvas
           onClick={this.handleMouseClick}
           zoomLimitsSelector={graphZoomLimitsSelector}
           zoomStateSelector={graphZoomStateSelector}
-          disabled={selectedNodeId}>
-          <EdgeMarkerDefinition selectedNodeId={selectedNodeId} />
-          <NodesChartElements />
+          disabled={this.props.selectedNodeId}>
+          {transform => this.renderContent(transform)}
         </ZoomableCanvas>
       </div>
     );
diff --git a/client/app/scripts/components/nodes-resources.js b/client/app/scripts/components/nodes-resources.js
index 50f257ab3..28d91d182 100644
--- a/client/app/scripts/components/nodes-resources.js
+++ b/client/app/scripts/components/nodes-resources.js
@@ -39,8 +39,8 @@ class NodesResources extends React.Component {
     return (
       <div className="nodes-resources">
         <ZoomableCanvas
+          bounded fixVertical
           onClick={this.handleMouseClick}
-          bounded forwardTransform fixVertical
           zoomLimitsSelector={resourcesZoomLimitsSelector}
           zoomStateSelector={resourcesZoomStateSelector}>
           {transform => this.renderLayers(transform)}
diff --git a/client/app/scripts/components/zoomable-canvas.js b/client/app/scripts/components/zoomable-canvas.js
index 1f5264795..a37dca26a 100644
--- a/client/app/scripts/components/zoomable-canvas.js
+++ b/client/app/scripts/components/zoomable-canvas.js
@@ -1,4 +1,5 @@
 import React from 'react';
+import classNames from 'classnames';
 import { connect } from 'react-redux';
 import { clamp, debounce, pick } from 'lodash';
 import { fromJS } from 'immutable';
@@ -10,7 +11,6 @@ import Logo from '../components/logo';
 import ZoomControl from '../components/zoom-control';
 import { cacheZoomState } from '../actions/app-actions';
 import { zoomFactor } from '../utils/zoom-utils';
-import { transformToString } from '../utils/transform-utils';
 import { activeTopologyZoomCacheKeyPathSelector } from '../selectors/zooming';
 import {
   canvasMarginsSelector,
@@ -35,6 +35,7 @@ class ZoomableCanvas extends React.Component {
     super(props, context);
 
     this.state = {
+      isPanning: false,
       minTranslateX: 0,
       maxTranslateX: 0,
       minTranslateY: 0,
@@ -50,16 +51,23 @@ class ZoomableCanvas extends React.Component {
     this.debouncedCacheZoom = debounce(this.cacheZoom.bind(this), ZOOM_CACHE_DEBOUNCE_INTERVAL);
     this.handleZoomControlAction = this.handleZoomControlAction.bind(this);
     this.canChangeZoom = this.canChangeZoom.bind(this);
+
     this.handleZoom = this.handleZoom.bind(this);
+    this.handlePanStart = this.handlePanStart.bind(this);
+    this.handlePanEnd = this.handlePanEnd.bind(this);
     this.handlePan = this.handlePan.bind(this);
   }
 
   componentDidMount() {
-    this.zoomRestored = false;
-    this.svg = select('svg#canvas');
-    this.drag = drag().on('drag', this.handlePan);
+    this.svg = select('.zoomable-canvas svg');
+    this.drag = drag()
+      .on('start', this.handlePanStart)
+      .on('end', this.handlePanEnd)
+      .on('drag', this.handlePan);
     this.svg.call(this.drag);
 
+    this.zoomRestored = false;
+
     this.updateZoomLimits(this.props);
     this.restoreZoomState(this.props);
   }
@@ -96,21 +104,14 @@ class ZoomableCanvas extends React.Component {
   }
 
   render() {
-    // `forwardTransform` says whether the zoom transform is forwarded to the child
-    // component. The advantage of that is more control rendering control in the
-    // children, while the disadvantage is that it's slower, as all the children
-    // get updated on every zoom/pan action.
-    const { children, forwardTransform } = this.props;
-    const transform = forwardTransform ? '' : transformToString(this.state);
+    const className = classNames({ panning: this.state.isPanning });
 
     return (
       <div className="zoomable-canvas">
-        <svg
-          id="canvas" width="100%" height="100%"
-          onClick={this.props.onClick} onWheel={this.handleZoom}>
+        <svg className={className} onClick={this.props.onClick} onWheel={this.handleZoom}>
           <Logo transform="translate(24,24) scale(0.25)" />
-          <g className="zoom-content" transform={transform}>
-            {forwardTransform ? children(this.state) : children}
+          <g className="zoom-content">
+            {this.props.children(this.state)}
           </g>
         </svg>
         {this.canChangeZoom() && <ZoomControl
@@ -158,6 +159,14 @@ class ZoomableCanvas extends React.Component {
     return !disabled && canvasHasContent;
   }
 
+  handlePanStart() {
+    this.setState({ isPanning: true });
+  }
+
+  handlePanEnd() {
+    this.setState({ isPanning: false });
+  }
+
   handlePan() {
     let state = { ...this.state };
     state = this.clampedTranslation({ ...state,
@@ -179,40 +188,22 @@ class ZoomableCanvas extends React.Component {
   }
 
   clampedTranslation(state) {
-    if (this.props.bounded) {
-      const { width, height, canvasMargins } = this.props;
-      const { maxTranslateX, minTranslateX, maxTranslateY, minTranslateY }
-        = this.props.layoutZoomLimits.toJS();
+    const { width, height, canvasMargins, bounded } = this.props;
+    const { maxTranslateX, minTranslateX, maxTranslateY, minTranslateY }
+      = this.props.layoutZoomLimits.toJS();
 
+    if (bounded) {
       const minPoint = transformF({ x: minTranslateX, y: minTranslateY }, state);
       const maxPoint = transformF({ x: maxTranslateX, y: maxTranslateY }, state);
       const viewportMinPoint = { x: canvasMargins.left, y: canvasMargins.top };
       const viewportMaxPoint = { x: canvasMargins.left + width, y: canvasMargins.top + height };
 
-      if (true) {
-        if (maxPoint.x < viewportMaxPoint.x) {
-          state.translateX += viewportMaxPoint.x - maxPoint.x;
-        } else if (minPoint.x > viewportMinPoint.x) {
-          state.translateX -= minPoint.x - viewportMinPoint.x;
-        }
-        if (maxPoint.y < viewportMaxPoint.y) {
-          state.translateY += viewportMaxPoint.y - maxPoint.y;
-        } else if (minPoint.y > viewportMinPoint.y) {
-          state.translateY -= minPoint.y - viewportMinPoint.y;
-        }
-      } else {
-        if (minPoint.x > viewportMaxPoint.x) {
-          state.translateX -= minPoint.x - viewportMaxPoint.x;
-        } else if (maxPoint.x < viewportMinPoint.x) {
-          state.translateX += viewportMinPoint.x - maxPoint.x;
-        }
-        if (minPoint.y > viewportMaxPoint.y) {
-          state.translateY -= minPoint.y - viewportMaxPoint.y;
-        } else if (maxPoint.y < viewportMinPoint.y) {
-          state.translateY += viewportMinPoint.y - maxPoint.y;
-        }
-      }
+      state.translateX += Math.max(0, viewportMaxPoint.x - maxPoint.x);
+      state.translateX += Math.min(0, viewportMinPoint.x - minPoint.x);
+      state.translateY += Math.max(0, viewportMaxPoint.y - maxPoint.y);
+      state.translateY += Math.min(0, viewportMinPoint.y - minPoint.y);
     }
+
     return state;
   }
 
diff --git a/client/app/styles/_base.scss b/client/app/styles/_base.scss
index a859eb655..e2ccdfc98 100644
--- a/client/app/styles/_base.scss
+++ b/client/app/styles/_base.scss
@@ -358,6 +358,15 @@ a {
   }
 }
 
+.zoomable-canvas {
+  svg {
+    @extend .grabbable;
+    width: 100%;
+    height: 100%;
+
+    &.panning { @extend .grabbing; }
+  }
+}
 
 .topologies {
   margin: 0 4px;