Slicer4:ViewerDesign

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Project Description

Ron would like to see a scalable architecture for the visual appearance of Slicer viewers as we add more types of elements and more of them. This architecture will also need to be able to accommodate new types of viewers such as graphs and tables.

We would also like to prepare a guide for developers of new types of viewers:

• that ensures that all viewers have a consistent visual and interaction design,
• and that makes it simpler for a developer to implement their viewer.

Slicer Reserved Colors and Viewer Colors Registry

Draft palette for viewer colors

Draft palette for viewer colors against which developers register

Color	Name	Use	Developer(s)	HEX	RGB
	White	Indicates active slice/frame in a multi-slice/frame viewer.	Core	#ffffff	255 255 255
	Grey	Generic Slice Viewers	Core	#8c8c8c	140 140 140
	Grey1	Unused	None	#a8aac2	168 170 194
	Grey2	Unused	None	#787b93	120 123 147
	Grey3	Unused	None	#5b5e71	91 94 113
	Grey4	Unused	None	#434450	67 68 80
	Black	3D Viewer Background & Default Widget Text	Core	#000000	0 0 0
	Yellow	Saggital Slice Viewer	Core	#e6cf49	230 207 73
	Cream	Unused	None	#faf8dd	250 248 221
	Wheat	Unused	None	#ded6a5	222 214 165
	Buff Yellow	Unused	None	#d5d86f	213 216 111
	Yellow Ochre	Unused	None	#c19a1c	193 154 28
	Camel	Unused	None	#765d10	118 93 16
	Red	Axial Slice Viewer	Core	#ef4832	239 72 50
	Light Red	Unused	None	#d5a6a5	213 166 165
	Magenta	Unused	None	#954473	149 68 115
	Rose	Unused	None	#9f5668	159 86 104
	Brick	Unused	None	#703543	112 53 67
	Burgundy	Unused	None	#7f2430	127 36 48
	Green	Coronal Slice Viewer	Core	#6cad49	108 173 73
	Soft Green	Unused	None	#91ae6f	145 174 111
	Moss Green	Unused	None	#898e26	137 142 38
	Cool Green	Unused	None	#81cf9f	129 207 159
	Summer Green	Unused	None	#3d7b5d	61 123 93
	Dark Green	Unused	None	#455535	69 85 53
	Blue	3D Viewers	Core	#707ee2	112 126 226
	Slicer Blue	Default background on 3D Viewers	Core	#a2a0e0	162 160 224
	Steel Blue	Unused	None	#d3d4f9	211 212 249
	Slate Blue	Unused	None	#6b8b93	107 139 147
	Water Blue	Unused	None	#327dbc	50 125 188
	Turquoise	Unused	None	#3b6a81	59 106 129
	Dark Blue	Unused	None	#3b4a71	59 74 113
	Lilac	Unused	None	#e3cfe9	227 207 233
	Lavender	Unused	None	#b095bb	176 149 187
	Cool Purple	Unused	None	#6b629c	107 98 156
	Violet	Charts (purple plots)	None	#6e4b7c	110 75 124
	Dark Violet	Unused	None	#4a3b54	74 59 84
	Orange	Compare Viewers	Core	#de6e11	222 110 17
	Peach	Unused	None	#ffd59f	255 213 159
	Light Orange	Unused	None	#eba965	235 169 101
	Rust	Unused	None	#aa4b1a	170 75 26
	Clay Brown	Unused	None	#a16643	161 102 67
	Dark Brown	Unused	None	#5b4c37	91 76 55

useful references

• Useful for extending: http://www.w3.org/TR/SVG/types.html#ColorKeywords ColorKeywords] for names of colors
• see also the Slicer 3 Colors

Notebook for Slicer 4 Presentation Layer Design

Notes & Sketches (Chronologically listed)

On Color-coding viewers & Qt Colors

Slicer default appearance as of 7-32: Slim-line color bars with sliders and pop up

• (from Jim) Many of the viewers we are using colors from the Qt palette. The viewer "name" is color alias that is recognized by Qt. But it doesn't need to be this way. We could always go through a lookup to map viewers with nonstandard color names as the viewer name to a RGB triple. We'll just need to slip in that mapping in the appropriate places. Qt accepts "named colors" from the SVG color keywords. See http://www.w3.org/TR/SVG/types.html#ColorKeywords. Qt can also take ANY color specified as RGB, HSV, etc. components.
  • Views (layouts) associated with SliceNodes have an attribute in their XML description for "viewcolor". This allows the name of the view to be decoupled from the color of the view. "viewcolor" is typically specified as a "#RRGGBB" string.

• (from Julien) There are 2 kinds of palettes:
  • a general "Qt application GUI" palette (color of the background, buttons, text, shadings, highlight color). This is QPalette.
  • a Slicer/MRML specific palette: color of the slice views, renderer background color of the 3D view, highlight of current view (slice or 3D). For now there is no placeholder for such a palette. I somewhat started to gather them in qMRMLColors.h/cxx. However, I believe it should be a VTK/MRML palette. Where MRML could provide a default palette, that can be extended/replaced by a Slicer palette.

• (from Julien) I've noticed there has been some work done in the past to allow such kind of feature: Slicer4\Modules\Meshing\BuildingBlock\vtkSlicerColor.h/cxx. I'm not sure in what extend we could reuse/generalize that work. For information, vtkMRMLViewNode already hardcodes the light blue background color.

• (question from Julien) Shall we make such a palette a singleton in MRML, or should it be a vtkMRMLScene member, other ideas ?

• (from Jim) The colors for the various viewers feels more like "application settings" or "look and feel" than MRML. I don't feel strongly about this but I wonder if the colors just need to be accessible from the Application object. I guess since we store things like the layout in MRML, it would make sense for the available colors to decorate the UI also be established in MRML.

• (from Wen) A first suggestion for how to color-code and ID viewers -- straw man for discussion:

Mock-up from 8/02: Viewer type color coding and ID (need to revise this with new roll-over color bar)

• • Keep Slicer Axi/Sag/Cor color coding, and all other individual slice viewers are grey
  • Keep Compare Viewers Orange
  • Make 3D viewers blue (better shade than in mockup!)
  • darken down the hairline frame around all viewers so "active" viewer is more apparent.
  • Multiple viewers of same viewer-type get a numerical ID
  • Create list of colors that developers register new viewer types to...
  • Helper code to create a viewer frame with same appearance & behavior

Mock-up from 8/02: Active Viewer Color = White for all viewer types (need to revise this with new roll-over color bar)

• • Question: Will we have more than one active viewer?
    • what would be a use case scenario?
    • what does active mean?

Mock-up from 8/02: Active Viewer Color = White for all viewer types (need to revise this with new roll-over color bar)

• • Lighten display up: if GUI panels are collapsed by default, and only expose on rollover, then we don't need to tie the image viewer to the color bar with a hairline of the same color. We can just use a just-noticeable grey divider which turns white on highlight. This may clean up the overall appearance a bit.

Mock-up from 8/02: Cleaner viewer appearance (need to revise this with new roll-over color bar)

• • Mockup with new rollover design. Larger area for rollover activation of controls and clicking to pin them open (easier to hit a larger target.) Gap between the hot area and the slice scroller to minimize mistakes. Slice numbers always visible and editable. Active window shown with a symbol and white outline.

Mock-up from 8/12. Cleaner viewer appearance and modified interaction -- for discussion.

• • Mockup with extra gap to minimize inter-viewer clicking mistakes.

Mock-up from 8/12 incorporating Ron's comments. Minimizing selection errors among viewers.

• • Mockup with link status displayed AND with recenter button exposed on 3D viewers as per Ron's suggestion. Suggestion to make controls hug the widget boundary on right viewer side (if controls exceed some minimum width requirement) to make it clearer that they belong to a viewer, rather than that they are an independent window full of widgets...

Mock-up from 8/15 incorporating Ron's comments. Expose link status and control to re-center 3D views. Non-orange highlights on compare view. (Does this require more problem-solving?)

Slice Controller scetches

Link to sketches for controllers

Summary from tcon discussion 8/2/2011: Three types of "colors" in Slicer4

1. Qt application "skin" which can be selected through an Application Settings interface. This includes background, buttons, text, shadings etc.

• This is implemented as a QPalette.

2. Slicer reserved colors that should-not be adjusted by the user.

• Colors of the roll-over bar on specific viewer types (Slice Red, Yellow, Green for example) should not change. This permits all Slicer users to discuss presentation of data in a consistent way, independent of how Slicer's presentation layer is styled.

3. MRML-specific colors that are restored with the scene. This includes 3D view background color, Fiducial color, etc.

• The set of color options are currently being collected in qMRMLColors.h/cxx.

QUESTIONS

• A question remains on which category color-styling of vtk widgets falls under (e.g. colors of widget handles and highlights). Importantly, widget handle and highlight colors form a visual language that a user understands (grab here, this grabbed guy is active, etc.) Changing these color codes is effectively breaking the rules of that language. A user has to experiment to verify that they understand the interactive behavior of the widget. For this reason, wjp recommends we categorize widget handle colors as color type "2" above -- Slicer-reserved that are not adjustable.
  • being able to change the color of a fiducial is important. E.g. I have two fiducial lists and I would like to make one bone colored and one vein colored. Is the color of the fiducial a handle?
• How to implement Color type 2 -- also as part of qMRMLColors.h/cxx?

SKINS

Alternative appropriate skins should be exposed as options under an Application Settings Interface. Skins that are tailored to different use cases (radiology reading room, or in the OR e.g.) are of interest. Skins may or may not be specified in the MRML scene, but if a scene is loaded, a user's skin should not change automatically -- maybe a viewer is prompted for whether they want to switch to the application interface appearance described in the scene file, or whether they want to preserve their own.

Julien has sent Wen instructions for how to create skins in Qt.