Select Rectangles to change their Lenths and Widths at once.
@Anonymous wrote:
.... in the Properties Palette ... of the Rectangles there are no rows with Length and Width of the selected Rectangle, so I can't change these important properties
so easy. .... there is not such Object Type as Rectangle in Autocad; ....
Consider the option of defining a Block that is a one-drawing-unit square, and Inserting that for rectangles, using the X and Y scale factors for the size. Then you would be able to change the length and width directly in the Properties Palette. [However, you wouldn't be able to do it by picking points on-screen except with some kind of routine. But a routine to change the X and/or Y scale factor(s) of an inserted Block to match picked distances would be quite simple.] One thing you would need to decide is whether the insertion point should be in the middle of the Block or at one of the corners [or you could have one of each].
Kent Cooper, AIA 
@marko_ribar wrote:
What will you do with delta width and delta length values, Kent?
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That's one of the easier parts to do [in a routine, of course -- you couldn't do it in the Properties Palette unless the current scale factors and the delta values are easy to combine in your head]. If the native Block is a one-unit square, then the X scale factor is its length, and the Y scale factor is its width [at least at 0 rotation and as the terms "length" and "width" are used in the Rectangle command's Dimensions option -- I would use X="width" and Y="height" if it were up to me]. If you want to use a delta value, you just get the appropriate current scale factor from the entity data or VLA properties, add/subtract the delta value to/from that, and impose the adjusted number back on it, either with (subst)/(entmod) or (vla-put...) methods. No calculation of new vertex locations required. Depending on whether you care which location in the Rectangle stays where it is, and where you've defined the insertion point in the Block definition, you might want to calculate a new insertion point for the Block reference, but that's only one positional calculation.
But it's all just a "consider the option" suggestion. Whether it makes sense depends a lot on what the rectangles represent and what they need to be able to do with them [other than adjust their size] or get from them. For instance, if they're Polylines, you can see their area or perimeter length directly in the Properties Palette just by picking on one, which you can't see with a Block. Conversely, determining the area of such a Block in a routine would be much easier than with Polyline entity data -- just multiply its X and Y scale factors. [There's a handy "Area" VLA property of Polylines that makes them easier in that regard if you go the (vla) route.] And narrowing down a selection to actual Rectangles would be infinitely simpler -- just filter for Block name [no need to check quantity of vertices, or equality of alternate segment lengths, or comparative segment directions, or whether closed or not, or any of that]. And you can see the angle of a Block's orientation directly in its Properties, which you can't see about a Polyline.
Kent Cooper, AIA
@Anonymous wrote:
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I wanted only lisp for "Select Rectangle(s) to change their Width and Height: "
"Specify New Width for these Rectangle(s): "
"Specify New Height for these Rectangle(s): "
"Edit position of every Rectangle (Enter to not to change position of specified Rectangle): "
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What do you mean by "not to change position" of a Rectangle? If its width and/or height are changed, its "position" must change in some respect. Do you mean to keep its midpoint in the same place [that would be my first assumption], in which case the position of at least some of its edges must change, or one of its corners [and if so, how to designate which one], or perhaps the middle of one of its edges, or... ?
And if the User chooses to "Edit position," how would that work? Would they be asked for a new location individually for each one? If so, again, what would be location relative to the Rectangle that would go at the selected new location?
Kent Cooper, AIA
@Anonymous wrote:
I meaned something like on the end of RECTANGLE command. .... you can choose one of four variants for position of the second Rectangle's corner.
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I would suggest the phrase "change the quadrant" of the Rectangle for that, in place of "Edit the position". If the User chooses to not change the quadrant, does that mean the original starting corner of the Rectangle should stay where it is, and other corners be adjusted from there for the new size? If the User chooses to change the quadrant, I can picture it might be easier to erase the Rectangle and make a new one starting from the original starting corner, but if the original is not orthogonally oriented [as RECTANG always makes them], the new one would then need to be Rotated to match the original. But it would be interesting to figure out how to ask for the quadrant they want if it's at an angle.
Kent Cooper, AIA
@marko_ribar wrote:
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And third small routine recc.lsp is made actually for drawing rectangles by center point... Couldn't find better way to acomplish this task than this - standard "RECTANGLE" command, and at the end move it so first picked point becomes rectangles center...
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Here's a routine that does that directly in-place -- RectMidPoint.lsp with its RMP command. It does have a few limitations that I haven't yet figured out how to overcome [see comments at the top, and down where the D for Dimensions option occurs], but it includes the regular Rectangle command's Fillet and Chamfer and Width and Elevation and Thickness options, and draws the Rectangle dynamically as you move the cursor around, and so on. [Also, I haven't yet updated its *error* function to remove the (command) function from it so Acad2015 won't complain.]
Kent Cooper, AIA