handle wrapping lines

Dependencies

• [2] 6RYLD5ON change how we handle clicks above top margin
• [3] LNUHQOGH start passing in Editor_state explicitly
• [4] 2L5MEZV3 experiment: new edit namespace
• [*] LXTTOB33 extract a couple of files
• [*] WAR3HXHT test both ways of selecting text with mouse

Change contents

• edit in text_tests.lua at line 850
  [7.543]

  [7.543]
  + function test_select_text_using_mouse_starting_above_text_wrapping_line()

  + -- first screen line starts in the middle of a line

  + App.screen.init{width=50, height=60}

  + Editor_state = edit.initialize_test_state()

  + Editor_state.lines = load_array{'abc', 'defgh', 'xyz'}

  + Text.redraw_all(Editor_state)

  + Editor_state.cursor1 = {line=2, pos=5}

  + Editor_state.screen_top1 = {line=2, pos=3}

  + Editor_state.screen_bottom1 = {}

  + -- press mouse above first line of text

  + edit.run_after_mouse_press(Editor_state, Editor_state.left+8,5, 1)

  + -- selection is at screen top

  + check(Editor_state.selection1.line ~= nil, 'selection:line-not-nil')

  + check_eq(Editor_state.selection1.line, 2, 'selection:line')

  + check_eq(Editor_state.selection1.pos, 3, 'selection:pos')

  + end

  +
• replacement in edit.lua at line 235
  [2.1226]→[2.1226:1257](∅→∅)
  − line=1,

  − pos=1,
  [2.1226]

  [2.1257]
  + line=State.screen_top1.line,

  + pos=State.screen_top1.pos,