fix wrong `Label.frame_body.x2` value (#2134)

* fix wrong `Label.frame_body.x2` value

`update_scroll_inset` might change `frame_inset`, i.e. we need to `computeFrame` with the new values.

* add tests for Label

* add missing `local`, remove code in comments

* move `TestFramedScreen` outside test functions

library/lua/gui/widgets.lua

@@ -478,8 +478,16 @@ function Label:render_scroll_icons(dc, x, y1, y2)
     end
 end
 
-function Label:postComputeFrame()
-    self:update_scroll_inset()
+function Label:computeFrame(parent_rect)
+    local frame_rect,body_rect = Label.super.computeFrame(self, parent_rect)
+
+    self.frame_rect = frame_rect
+    self.frame_body = parent_rect:viewport(body_rect or frame_rect)
+
+    self:update_scroll_inset() -- frame_body is now set
+
+    -- recalc with updated frame_inset
+    return Label.super.computeFrame(self, parent_rect)
 end
 
 function Label:preUpdateLayout()

test/library/gui/widgets.Label.lua

@@ -0,0 +1,94 @@
+-- test -dhack/scripts/devel/tests -twidgets.Label
+
+local gui = require('gui')
+local widgets = require('gui.widgets')
+
+local xtest = {} -- use to temporarily disable tests (change `function xtest.somename` to `function xxtest.somename`)
+local wait = function(n)
+    delay(n or 30) -- enable for debugging the tests
+end
+
+local fs = defclass(fs, gui.FramedScreen)
+fs.ATTRS = {
+    frame_style = gui.GREY_LINE_FRAME,
+    frame_title = 'TestFramedScreen',
+    frame_width = 10,
+    frame_height = 10,
+    frame_inset = 0,
+    focus_path = 'test-framed-screen',
+}
+
+function test.Label_correct_frame_body_with_scroll_icons()
+    local t = {}
+    for i = 1, 12 do
+        t[#t+1] = tostring(i)
+        t[#t+1] = NEWLINE
+    end
+
+    function fs:init(args)
+        self:addviews{
+            widgets.Label{
+                view_id = 'text',
+                frame_inset = 0,
+                text = t,
+                --show_scroll_icons = 'right',
+            },
+        }
+    end
+
+    local o = fs{}
+    --o:show()
+    --wait()
+    expect.eq(o.subviews.text.frame_body.width, 9, "Label's frame_body.x2 and .width should be one smaller because of show_scroll_icons.")
+    --o:dismiss()
+end
+
+function test.Label_correct_frame_body_with_few_text_lines()
+    local t = {}
+    for i = 1, 10 do
+        t[#t+1] = tostring(i)
+        t[#t+1] = NEWLINE
+    end
+
+    function fs:init(args)
+        self:addviews{
+            widgets.Label{
+                view_id = 'text',
+                frame_inset = 0,
+                text = t,
+                --show_scroll_icons = 'right',
+            },
+        }
+    end
+
+    local o = fs{}
+    --o:show()
+    --wait()
+    expect.eq(o.subviews.text.frame_body.width, 10, "Label's frame_body.x2 and .width should not change with show_scroll_icons = false.")
+    --o:dismiss()
+end
+
+function test.Label_correct_frame_body_without_show_scroll_icons()
+    local t = {}
+    for i = 1, 12 do
+        t[#t+1] = tostring(i)
+        t[#t+1] = NEWLINE
+    end
+
+    function fs:init(args)
+        self:addviews{
+            widgets.Label{
+                view_id = 'text',
+                frame_inset = 0,
+                text = t,
+                show_scroll_icons = false,
+            },
+        }
+    end
+
+    local o = fs{}
+    --o:show()
+    --wait()
+    expect.eq(o.subviews.text.frame_body.width, 10, "Label's frame_body.x2 and .width should not change with show_scroll_icons = false.")
+    --o:dismiss()
+end