DiagramWidget

.gitignore

@@ -40,3 +40,4 @@ Session.vim
 tags
 # Persistent undo
 [._]*.un~
+*.exe

AUTHORS

@@ -0,0 +1 @@
+Diagram Widget: Charles Daniels and Paul C. Brown

README.md

@@ -53,13 +53,33 @@ layout := NewResponsiveLayout(
 
 ## Widgets
 
-Community contributed widgets.
+This package contains a collection of community-contributed widgets for the [Fyne](https://fyne.io/) 
+toolkit. The code here is intended to be production ready, but may be lacking
+some desirable functional features. If you have suggestions for changes to 
+existing functionality or addition of new functionality, please look at the existing
+issues in the repository to see if your idea is already on the table. If it is not,
+feel free to open an issue. 
+
+This collection should be considered a work in progress. When changes are made,
+serious consideration will be given to backward compatibility, but compatibility
+is not guaranteed. 
 
 `import "fyne.io/x/fyne/widget"`
 
-### Calendar
+### Animated Gif
 
-
+A widget that will run animated gifs.
+
+<p align="center" class="align:center;margin:auto" markdown="1">
+<img src="img/gifwidget.gif" />
+</p>
+
+```go
+gif, err := NewAnimatedGif(storage.NewFileURI("./testdata/gif/earth.gif"))
+gif.Start()
+```
+
+### Calendar
 
 A date picker which returns a [time](https://pkg.go.dev/time) object with the selected date.
 
@@ -80,18 +100,30 @@ calendar := widget.NewCalendar(time.Now(), onSelected, cellSize, padding)
 ```
 [Demo](./cmd/hexwidget_demo/main.go) available for example usage
 
-### Animated Gif
+### DiagramWidget
 
-A widget that will run animated gifs.
+The DiagramWidget provides a drawing area within which a diagram can be created. The diagram itself is a collection of 
+DiagramElement widgets (an interface). There are two types of DiagramElements: DiagramNode widgets and DiagramLink widgets. 
+DiagramNode widgets are thin wrappers around a user-supplied CanvasObject.
+Any valid CanvasObject can be used. DiagramLinks are line-based connections between DiagramElements.
+Note that links can connect to other links as well as nodes.
 
-<p align="center" class="align:center;margin:auto" markdown="1">
-<img src="img/gifwidget.gif" />
+While some provisions have been made for automatic layout, layouts are for the convenience
+of the author and are on-demand only. The design intent is that users will place the diagram elements for human readability. 
+
+DiagramElements are managed by the DiagramWidget from a layout perspective. DiagramNodes have no size
+constraints imposed by the DiagramWidget and can be placed anywhere. DiagramLinks connect 
+DiagramElements. The DiagramWidget keeps track of the DiagramElements to which each DiagramLink 
+is connected and calls the Refresh() method on the link when the connected diagram element is moved 
+or resized. 
+
+* [demo](./cmd/diagramdemo/main.go)
+* [More Detail](./widget/diagramwidget/README.md)
+
+<p align="center" markdown="1" style="max-width: 100%">
+  <img src="img/diagramdemo.png" width="1024" height="880" alt="Diagram Widget" style="max-width: 100%" />
 </p>
 
-```go
-gif, err := NewAnimatedGif(storage.NewFileURI("./testdata/gif/earth.gif"))
-gif.Start()
-```
 
 ### FileTree
 

cmd/diagramdemo/main.go

@@ -0,0 +1,184 @@
+package main
+
+import (
+	"fmt"
+	"image/color"
+	"time"
+
+	"fyne.io/x/fyne/widget/diagramwidget"
+
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/app"
+	"fyne.io/fyne/v2/container"
+	"fyne.io/fyne/v2/widget"
+)
+
+var forceticks int = 0
+
+func forceanim(diagramWidget *diagramwidget.DiagramWidget) {
+
+	for {
+		if forceticks > 0 {
+			diagramwidget.StepForceLayout(diagramWidget, 300)
+			diagramWidget.Refresh()
+			forceticks--
+			fmt.Printf("forceticks=%d\n", forceticks)
+		}
+
+		time.Sleep(time.Millisecond * (1000 / 30))
+	}
+}
+
+func main() {
+	app := app.New()
+	w := app.NewWindow("Diagram Demo")
+
+	w.SetMaster()
+
+	diagramWidget := diagramwidget.NewDiagramWidget("Diagram1")
+
+	scrollContainer := container.NewScroll(diagramWidget)
+
+	go forceanim(diagramWidget)
+
+	// Node 0
+	node0Label := widget.NewLabel("Node0")
+	node0 := diagramwidget.NewDiagramNode(diagramWidget, node0Label, "Node0")
+	node0.Move(fyne.NewPos(300, 0))
+
+	// Node 1
+	node1Button := widget.NewButton("Node1 Button", func() { fmt.Printf("tapped Node1!\n") })
+	node1 := diagramwidget.NewDiagramNode(diagramWidget, node1Button, "Node1")
+	node1.Move(fyne.Position{X: 100, Y: 100})
+
+	// Node 2
+	node2 := diagramwidget.NewDiagramNode(diagramWidget, nil, "Node2")
+	node2Container := container.NewVBox(
+		widget.NewLabel("Node2 - with structure"),
+		widget.NewButton("Up", func() {
+			node2.GetDiagram().DisplaceNode(node2, fyne.Position{X: 0, Y: -10})
+			node2.Refresh()
+		}),
+		widget.NewButton("Down", func() {
+			node2.GetDiagram().DisplaceNode(node2, fyne.Position{X: 0, Y: 10})
+			node2.Refresh()
+		}),
+		container.NewHBox(
+			widget.NewButton("Left", func() {
+				node2.GetDiagram().DisplaceNode(node2, fyne.Position{X: -10, Y: 0})
+				node2.Refresh()
+			}),
+			widget.NewButton("Right", func() {
+				node2.GetDiagram().DisplaceNode(node2, fyne.Position{X: 10, Y: 0})
+				node2.Refresh()
+			}),
+		),
+	)
+	node2.SetInnerObject(node2Container)
+	node2.Move(fyne.Position{X: 100, Y: 300})
+
+	// Node 3
+	node3 := diagramwidget.NewDiagramNode(diagramWidget, widget.NewButton("Node3: Force layout step", func() {
+		diagramwidget.StepForceLayout(diagramWidget, 300)
+		diagramWidget.Refresh()
+	}), "Node3")
+	node3.Move(fyne.Position{X: 400, Y: 100})
+
+	// Node 4
+	node4 := diagramwidget.NewDiagramNode(diagramWidget, widget.NewButton("Node4: auto layout", func() {
+		forceticks += 100
+		diagramWidget.Refresh()
+	}), "Node4")
+	node4.Move(fyne.Position{X: 400, Y: 400})
+
+	node5 := diagramwidget.NewDiagramNode(diagramWidget, widget.NewLabel("Node5"), "Node5")
+	node5.Move(fyne.NewPos(600, 200))
+
+	// Link0
+	link0 := diagramwidget.NewDiagramLink(diagramWidget, "Link0")
+	link0.SetSourcePad(node0.GetEdgePad())
+	link0.SetTargetPad(node1.GetEdgePad())
+	link0.AddSourceAnchoredText("sourceRole", "sourceRole")
+	link0.AddMidpointAnchoredText("linkName", "Link 0")
+	solidDiamond := createDiamondDecoration()
+	solidDiamond.SetSolid(true)
+	link0.AddSourceDecoration(solidDiamond)
+
+	// Link1
+	link1 := diagramwidget.NewDiagramLink(diagramWidget, "Link1")
+	link1.SetSourcePad(node2.GetEdgePad())
+	link1.SetTargetPad(node1.GetEdgePad())
+	link1.SetForegroundColor(color.RGBA{255, 64, 64, 255})
+	link1.AddTargetDecoration(diagramwidget.NewArrowhead())
+	link1.AddTargetDecoration(diagramwidget.NewArrowhead())
+	link1.AddMidpointDecoration(diagramwidget.NewArrowhead())
+	link1.AddMidpointDecoration(diagramwidget.NewArrowhead())
+	link1.AddMidpointAnchoredText("linkName", "Link 1")
+	link1.AddSourceDecoration(diagramwidget.NewArrowhead())
+	link1.AddSourceDecoration(diagramwidget.NewArrowhead())
+
+	// Link2
+	link2 := diagramwidget.NewDiagramLink(diagramWidget, "Link2")
+	link2.SetSourcePad(node0.GetEdgePad())
+	link2.SetTargetPad(node3.GetEdgePad())
+	link2.AddMidpointAnchoredText("linkName", "Link 2")
+	link2.AddSourceDecoration(createHalfArrowDecoration())
+
+	// Link3
+	link3 := diagramwidget.NewDiagramLink(diagramWidget, "Link3")
+	link3.SetSourcePad(node2.GetEdgePad())
+	link3.SetTargetPad(node3.GetEdgePad())
+	link3.AddSourceAnchoredText("sourceRole", "sourceRole")
+	link3.AddMidpointAnchoredText("linkName", "Link 3")
+	link3.AddTargetAnchoredText("targetRole", "targetRole")
+	link3.AddMidpointDecoration(createTriangleDecoration())
+
+	// Link4
+	link4 := diagramwidget.NewDiagramLink(diagramWidget, "Link4")
+	link4.SetSourcePad(node4.GetEdgePad())
+	link4.SetTargetPad(node3.GetEdgePad())
+	link4.AddMidpointAnchoredText("linkName", "Link 4")
+
+	// Link5
+	link5 := diagramwidget.NewDiagramLink(diagramWidget, "Link5")
+	link5.SetSourcePad(link4.GetMidPad())
+	link5.SetTargetPad(node5.GetEdgePad())
+	link5.AddMidpointAnchoredText("linkName", "Link 5")
+	link5.AddTargetDecoration(diagramwidget.NewArrowhead())
+
+	w.SetContent(scrollContainer)
+
+	w.Resize(fyne.NewSize(600, 400))
+	w.ShowAndRun()
+}
+
+func createTriangleDecoration() diagramwidget.Decoration {
+	points := []fyne.Position{
+		{X: 0, Y: 15},
+		{X: 15, Y: 0},
+		{X: 0, Y: -15},
+	}
+	polygon := diagramwidget.NewPolygon(points)
+	return polygon
+}
+
+func createDiamondDecoration() diagramwidget.Decoration {
+	points := []fyne.Position{
+		{X: 0, Y: 0},
+		{X: 8, Y: 4},
+		{X: 16, Y: 0},
+		{X: 8, Y: -4},
+	}
+	polygon := diagramwidget.NewPolygon(points)
+	return polygon
+}
+
+func createHalfArrowDecoration() diagramwidget.Decoration {
+	points := []fyne.Position{
+		{X: 0, Y: 0},
+		{X: 16, Y: 8},
+		{X: 16, Y: 0},
+	}
+	polygon := diagramwidget.NewPolygon(points)
+	return polygon
+}

go.mod

@@ -8,7 +8,9 @@ require (
 	github.com/eclipse/paho.mqtt.golang v1.3.5
 	github.com/gorilla/websocket v1.4.2
 	github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646
+	github.com/srwiley/rasterx v0.0.0-20220730225603-2ab79fcdd4ef
 	github.com/stretchr/testify v1.8.4
+	github.com/twpayne/go-geom v1.0.0
 	github.com/wagslane/go-password-validator v0.3.0
 	golang.org/x/image v0.11.0
 )

go.sum

@@ -302,6 +302,10 @@ github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXl
 github.com/subosito/gotenv v1.2.0/go.mod h1:N0PQaV/YGNqwC0u51sEeR/aUtSLEXKX9iv69rRypqCw=
 github.com/tevino/abool v1.2.0 h1:heAkClL8H6w+mK5md9dzsuohKeXHUpY7Vw0ZCKW+huA=
 github.com/tevino/abool v1.2.0/go.mod h1:qc66Pna1RiIsPa7O4Egxxs9OqkuxDX55zznh9K07Tzg=
+github.com/twpayne/go-geom v1.0.0 h1:ARrRnN4+rBX3LZFZQy9NFeXXlgQqVL4OOvAcnLdgy2g=
+github.com/twpayne/go-geom v1.0.0/go.mod h1:RWsl+e3XSahOul/KH2BHCfF0QxSL4RMnMlFw/TNmET0=
+github.com/twpayne/go-kml v1.0.0/go.mod h1:LlvLIQSfMqYk2O7Nx8vYAbSLv4K9rjMvLlEdUKWdjq0=
+github.com/twpayne/go-polyline v1.0.0/go.mod h1:ICh24bcLYBX8CknfvNPKqoTbe+eg+MX1NPyJmSBo7pU=
 github.com/urfave/cli/v2 v2.4.0/go.mod h1:NX9W0zmTvedE5oDoOMs2RTC8RvdK98NTYZE5LbaEYPg=
 github.com/wagslane/go-password-validator v0.3.0 h1:vfxOPzGHkz5S146HDpavl0cw1DSVP061Ry2PX0/ON6I=
 github.com/wagslane/go-password-validator v0.3.0/go.mod h1:TI1XJ6T5fRdRnHqHt14pvy1tNVnrwe7m3/f1f2fDphQ=