VirtualKeyboard: Revamp visibility handling (#10852)

Move as much of the state tracking as possible inside VirtualKeyboard itself.
InputDialog unfortunately needs an internal tracking of this state because it needs to know about it *before* the VK is shown, so we have to keep a bit of duplication in there, although we do try much harder to keep everything in sync (at least at function call edges), and to keep the damage contained to, essentially, the toggle button's handler.

(Followup to #10803 & #10850)

frontend/apps/reader/modules/readerstyletweak.lua

@@ -920,10 +920,10 @@ function ReaderStyleTweak:editBookTweak(touchmenu_instance)
                 end
             end
         end,
-        -- Set/save view and cursor position callback
+        -- Store/retrieve view and cursor position callback
         view_pos_callback = function(top_line_num, charpos)
-            -- This same callback is called with no argument to get initial position,
+            -- This same callback is called with no arguments on init to retrieve the stored initial position,
-            -- and with arguments to give back final position when closed.
+            -- and with arguments to store the final position on close.
             if top_line_num and charpos then
                 self.book_style_tweak_last_edit_pos = {top_line_num, charpos}
             else

frontend/ui/widget/inputdialog.lua

@@ -141,7 +141,7 @@ local InputDialog = FocusManager:extend{
     add_scroll_buttons = false, -- add scroll Up/Down buttons to first row of buttons
     add_nav_bar = false, -- append a row of page navigation buttons
         -- note that the text widget can be scrolled with Swipe North/South even when no button
-    keyboard_hidden = false, -- start with keyboard hidden in full fullscreen mode
+    keyboard_visible = true, -- whether we start with the keyboard visible or not (i.e., our caller skipped onShowKeyboard)
                              -- needs add_nav_bar to have a Show keyboard button to get it back
     scroll_by_pan = false, -- allow scrolling by lines with Pan (= Swipe, but wait a bit at end
                            -- of gesture before releasing) (may conflict with movable)
@@ -162,8 +162,8 @@ local InputDialog = FocusManager:extend{
     edited_callback = nil,  -- Called on each text modification
 
     -- For use by TextEditor plugin:
-    view_pos_callback = nil, -- Called with no arg to get initial top_line_num/charpos,
+    view_pos_callback = nil, -- Called with no args on init to retrieve top_line_num/charpos (however the caller chooses to do so, e.g., some will store it in a LuaSettings),
-                             -- called with (top_line_num, charpos) to give back position on close.
+                             -- called with (top_line_num, charpos) on close to let the callback do its thing so that the no args branch spits back useful data..
 
     -- Set to false if movable gestures conflicts with subwidgets gestures
     is_movable = true,
@@ -189,6 +189,7 @@ local InputDialog = FocusManager:extend{
     alignment_strict = false,
 
     -- for internal use
+    _keyboard_was_visible = nil, -- previous kb visibility state
     _text_modified = false, -- previous known modified status
     _top_line_num = nil,
     _charpos = nil,
@@ -216,7 +217,7 @@ function InputDialog:init()
         self.text_width = self.text_width or math.floor(self.width * 0.9)
     end
     if self.readonly then -- hide keyboard if we can't edit
-        self.keyboard_hidden = true
+        self.keyboard_visible = false
     end
     if self.fullscreen or self.add_nav_bar then
         self.deny_keyboard_hiding = true
@@ -299,10 +300,7 @@ function InputDialog:init()
         local text_height = input_widget:getTextHeight()
         local line_height = input_widget:getLineHeight()
         local input_pad_height = input_widget:getSize().h - text_height
-        local keyboard_height = 0
+        local keyboard_height = self.keyboard_visible and input_widget:getKeyboardDimen().h or 0
-        if not self.keyboard_hidden then
-            keyboard_height = input_widget:getKeyboardDimen().h
-        end
         input_widget:onCloseWidget() -- free() textboxwidget and keyboard
         -- Find out available height
         local available_height = self.screen_height
@@ -331,9 +329,14 @@ function InputDialog:init()
         end
     end
     if self.view_pos_callback then
-        -- Get initial cursor and top line num from callback
+        -- Retrieve cursor position and top line num from our callback.
-        -- (will work in case of re-init as these are saved by onClose()
+        -- Mainly used for runtime re-inits.
-        self._top_line_num, self._charpos = self.view_pos_callback()
+        -- c.f., our onClose handler for the other end of this.
+        -- *May* return nils, in which case, we do *not* want to override our caller's values!
+        local top_line_num, charpos = self.view_pos_callback()
+        if top_line_num and charpos then
+            self._top_line_num, self._charpos = top_line_num, charpos
+        end
     end
     self._input_widget = self.inputtext_class:new{
         text = self.input,
@@ -368,7 +371,6 @@ function InputDialog:init()
         scroll_by_pan = self.scroll_by_pan,
         cursor_at_end = self.cursor_at_end,
         readonly = self.readonly,
-        manage_keyboard_state = not self.add_nav_bar, -- we handle keyboard toggle ourselve if nav_bar
         parent = self,
         is_text_edited = self._text_modified,
         top_line_num = self._top_line_num,
@@ -423,8 +425,7 @@ function InputDialog:init()
         }
         frame = self.movable
     end
-    local keyboard_height = self.keyboard_hidden and 0
+    local keyboard_height = self.keyboard_visible and self._input_widget:getKeyboardDimen().h or 0
-                                or self._input_widget:getKeyboardDimen().h
     self[1] = CenterContainer:new{
         dimen = Geom:new{
             w = self.screen_width,
@@ -449,6 +450,11 @@ function InputDialog:init()
             self:addWidget(widget, true)
         end
     end
+
+    -- If we're fullscreen without a keyboard, make sure only the toggle button can show the keyboard...
+    if self.fullscreen and not self.keyboard_visible then
+        self:lockKeyboard(true)
+    end
 end
 
 function InputDialog:addWidget(widget, re_init)
@@ -474,13 +480,13 @@ function InputDialog:getAddedWidgetAvailableWidth()
     return self._input_widget.width
 end
 
+-- Close the keyboard if we tap anywhere outside of the keyboard (that isn't an input field, where it would be caught via InputText:onTapTextBox)
 function InputDialog:onTap()
+    -- This is slightly more fine-grained than VK's own visibility lock, hence the duplication...
     if self.deny_keyboard_hiding then
         return
     end
-    if self._input_widget.onCloseKeyboard then
+    self:onCloseKeyboard()
-        self._input_widget:onCloseKeyboard()
-    end
 end
 
 function InputDialog:getInputText()
@@ -525,24 +531,79 @@ function InputDialog:onCloseWidget()
 end
 
 function InputDialog:onShowKeyboard(ignore_first_hold_release)
-    if not self.readonly and not self.keyboard_hidden then
+    -- NOTE: There's no VirtualKeyboard widget instantiated at all when readonly,
+    --       and our input widget handles that itself, so we don't need any guards here.
+    --       (In which case, isKeyboardVisible will return `nil`, same as if we had a VK instantiated but *never* shown).
     self._input_widget:onShowKeyboard(ignore_first_hold_release)
-    end
+    -- There's a bit of a chicken or egg issue in init where we would like to check the actual keyboard's visibility state,
+    -- but the widget might not exist or be shown yet, so we'll just have to keep this in sync...
+    self.keyboard_visible = self._input_widget:isKeyboardVisible()
+end
+
+function InputDialog:onCloseKeyboard()
+    self._input_widget:onCloseKeyboard()
+    self.keyboard_visible = self._input_widget:isKeyboardVisible()
+end
+
+function InputDialog:isKeyboardVisible()
+    return self._input_widget:isKeyboardVisible()
+end
+
+function InputDialog:lockKeyboard(toggle)
+    return self._input_widget:lockKeyboard(toggle)
+end
+
+-- NOTE: Only called by fullscreen and/or add_nav_bar codepaths
+--       We do not currently have !fullscreen add_nav_bar callers...
+function InputDialog:toggleKeyboard(force_toggle)
+    -- Remember the *current* visibility, as the following close will reset it
+    local visible = self:isKeyboardVisible()
+
+    -- When we forcibly close the keyboard, remember its current visiblity state, so that we can properly restore it later.
+    -- (This is used by some buttons in fullscreen mode, where we might want to keep the original keyboard hidden when popping up a new one for another InputDialog).
+    if force_toggle == false then
+        -- NOTE: visible will be nil between our own init and a show of the keyboard, which is precisely what happens when we *hide* the keyboard.
+        self._keyboard_was_visible = visible == true
     end
 
-function InputDialog:toggleKeyboard(force_hide)
-    if force_hide and self.keyboard_hidden then return end
-    self.keyboard_hidden = not self.keyboard_hidden
     self.input = self:getInputText() -- re-init with up-to-date text
     self:onClose() -- will close keyboard and save view position
     self:free()
-    self:init()
+
-    if not self.keyboard_hidden then
+    if force_toggle == false and not visible then
-        self:onShowKeyboard()
+        -- Already hidden, bye!
+        return
     end
+
+    -- Init needs to know the keyboard's visibility state *before* the widget is actually shown...
+    if force_toggle == true then
+        self.keyboard_visible = true
+    elseif force_toggle == false then
+        self.keyboard_visible = false
+    elseif self._keyboard_was_visible ~= nil then
+        self.keyboard_visible = self._keyboard_was_visible
+        self._keyboard_was_visible = nil
+    else
+        self.keyboard_visible = not visible
+    end
+    self:init()
+
+    -- NOTE: If we ever have non-fullscreen add_nav_bar callers, it might make sense *not* to lock the keyboard there?
+    if self.keyboard_visible then
+        self:lockKeyboard(false)
+        self:onShowKeyboard()
+    else
+        self:onCloseKeyboard()
+        -- Prevent InputText:onTapTextBox from opening the keyboard back up on top of our buttons
+        self:lockKeyboard(true)
+    end
+
+    -- Make sure we refresh the nav bar, as it will have moved, and it belongs to us, not to VK or our input widget...
+    self:refreshButtons()
 end
 
 function InputDialog:onKeyboardHeightChanged()
+    local visible = self:isKeyboardVisible()
     self.input = self:getInputText() -- re-init with up-to-date text
     self:onClose() -- will close keyboard and save view position
     self._input_widget:onCloseWidget() -- proper cleanup of InputText and its keyboard
@@ -555,8 +616,11 @@ function InputDialog:onKeyboardHeightChanged()
     self:free()
     -- Restore original text_height (or reset it if none to force recomputing it)
     self.text_height = self.orig_text_height or nil
+
+    -- Same deal as in toggleKeyboard...
+    self.keyboard_visible = visible
     self:init()
-    if not self.keyboard_hidden then
+    if self.keyboard_visible then
         self:onShowKeyboard()
     end
     -- Our position on screen has probably changed, so have the full screen refreshed
@@ -573,14 +637,16 @@ function InputDialog:onCloseDialog()
 end
 
 function InputDialog:onClose()
+    -- Tell our input widget to poke its text widget so that we'll pickup up to date values
+    self._input_widget:resyncPos()
     -- Remember current view & position in case of re-init
     self._top_line_num = self._input_widget.top_line_num
     self._charpos = self._input_widget.charpos
     if self.view_pos_callback then
-        -- Give back top line num and cursor position
+        -- This lets the caller store/process the current top line num and cursor position via this callback
         self.view_pos_callback(self._top_line_num, self._charpos)
     end
-    self._input_widget:onCloseKeyboard()
+    self:onCloseKeyboard()
 end
 
 function InputDialog:refreshButtons()
@@ -764,7 +830,7 @@ function InputDialog:_addScrollButtons(nav_bar)
         -- Also add Keyboard hide/show button if we can
         if self.fullscreen and not self.readonly then
             table.insert(row, {
-                text = self.keyboard_hidden and "↑⌨" or "↓⌨",
+                text = self.keyboard_visible and "↓⌨" or "↑⌨",
                 id = "keyboard",
                 callback = function()
                     self:toggleKeyboard()
@@ -776,8 +842,7 @@ function InputDialog:_addScrollButtons(nav_bar)
             table.insert(row, {
                 text = _("Find"),
                 callback = function()
-                    local keyboard_hidden_state = not self.keyboard_hidden
+                    self:toggleKeyboard(false) -- hide text editor keyboard
-                    self:toggleKeyboard(true) -- hide text editor keyboard
                     local input_dialog
                     input_dialog = InputDialog:new{
                         title = _("Enter text to search for"),
@@ -790,21 +855,20 @@ function InputDialog:_addScrollButtons(nav_bar)
                                     id = "close",
                                     callback = function()
                                         UIManager:close(input_dialog)
-                                        self.keyboard_hidden = keyboard_hidden_state
                                         self:toggleKeyboard()
                                     end,
                                 },
                                 {
                                     text = _("Find first"),
                                     callback = function()
-                                        self:findCallback(keyboard_hidden_state, input_dialog, true)
+                                        self:findCallback(input_dialog, true)
                                     end,
                                 },
                                 {
                                     text = _("Find next"),
                                     is_enter_default = true,
                                     callback = function()
-                                        self:findCallback(keyboard_hidden_state, input_dialog)
+                                        self:findCallback(input_dialog)
                                     end,
                                 },
                             },
@@ -829,8 +893,7 @@ function InputDialog:_addScrollButtons(nav_bar)
             table.insert(row, {
                 text = _("Go"),
                 callback = function()
-                    local keyboard_hidden_state = not self.keyboard_hidden
+                    self:toggleKeyboard(false) -- hide text editor keyboard
-                    self:toggleKeyboard(true) -- hide text editor keyboard
                     local cur_line_num, last_line_num = self._input_widget:getLineNums()
                     local input_dialog
                     input_dialog = InputDialog:new{
@@ -846,7 +909,6 @@ function InputDialog:_addScrollButtons(nav_bar)
                                     id = "close",
                                     callback = function()
                                         UIManager:close(input_dialog)
-                                        self.keyboard_hidden = keyboard_hidden_state
                                         self:toggleKeyboard()
                                     end,
                                 },
@@ -857,7 +919,6 @@ function InputDialog:_addScrollButtons(nav_bar)
                                         local new_line_num = tonumber(input_dialog:getInputText())
                                         if new_line_num and new_line_num >= 1 and new_line_num <= last_line_num then
                                             UIManager:close(input_dialog)
-                                            self.keyboard_hidden = keyboard_hidden_state
                                             self:toggleKeyboard()
                                             self._input_widget:moveCursorToCharPos(self._input_widget:getLineCharPos(new_line_num))
                                         end
@@ -939,11 +1000,10 @@ function InputDialog:_addScrollButtons(nav_bar)
     end
 end
 
-function InputDialog:findCallback(keyboard_hidden_state, input_dialog, find_first)
+function InputDialog:findCallback(input_dialog, find_first)
     self.search_value = input_dialog:getInputText()
     if self.search_value == "" then return end
     UIManager:close(input_dialog)
-    self.keyboard_hidden = keyboard_hidden_state
     self:toggleKeyboard()
     local start_pos = find_first and 1 or self._charpos + 1
     local char_pos = util.stringSearch(self.input, self.search_value, self.case_sensitive, start_pos)

frontend/ui/widget/inputtext.lua

@@ -32,9 +32,8 @@ local InputText = InputContainer:extend{
     focused = true,
     parent = nil, -- parent dialog that will be set dirty
     edit_callback = nil, -- called with true when text modified, false on init or text re-set
-    scroll_callback = nil, -- called with (low, high) when view is scrolled (cf ScrollTextWidget)
+    scroll_callback = nil, -- called with (low, high) when view is scrolled (c.f., ScrollTextWidget)
     scroll_by_pan = false, -- allow scrolling by lines with Pan (needs scroll=true)
-    manage_keyboard_state = true, -- manage keyboard hidden/shown state
 
     width = nil,
     height = nil, -- when nil, will be set to original text height (possibly
@@ -54,7 +53,10 @@ local InputText = InputContainer:extend{
     auto_para_direction = false,
     alignment_strict = false,
 
+    readonly = nil, -- will not support a Keyboard widget if true
+
     -- for internal use
+    keyboard = nil, -- Keyboard widget (either VirtualKeyboard or PhysicalKeyboard)
     text_widget = nil, -- Text Widget for cursor movement, possibly a ScrollTextWidget
     charlist = nil, -- table of individual chars from input string
     charpos = nil, -- position of the cursor, where a new char would be inserted
@@ -65,7 +67,6 @@ local InputText = InputContainer:extend{
     for_measurement_only = nil, -- When the widget is a one-off used to compute text height
     do_select = false, -- to start text selection
     selection_start_pos = nil, -- selection start position
-    is_keyboard_hidden = true, -- to be able to show the keyboard again when it was hidden. (On init, it's the caller's responsibility to call onShowKeyboard, as far as we're concerned, it's hidden)
 }
 
 -- These may be (internally) overloaded as needed, depending on Device capabilities.
@@ -73,6 +74,11 @@ function InputText:initEventListener() end
 function InputText:onFocus() end
 function InputText:onUnfocus() end
 
+-- Resync our position state with our text widget's actual state
+function InputText:resyncPos()
+    self.charpos, self.top_line_num = self.text_widget:getCharPos()
+end
+
 local function initTouchEvents()
     if Device:isTouchDevice() then
         function InputText:initEventListener()
@@ -133,8 +139,8 @@ local function initTouchEvents()
             if self.parent.onSwitchFocus then
                 self.parent:onSwitchFocus(self)
             else
-                if self.is_keyboard_hidden and self.manage_keyboard_state then
+                if self.keyboard then
-                    self:onShowKeyboard()
+                    self.keyboard:showKeyboard()
                 end
             end
             -- zh keyboard with candidates shown here has _frame_textwidget.dimen = nil.
@@ -144,7 +150,7 @@ local function initTouchEvents()
                 local x = ges.pos.x - self._frame_textwidget.dimen.x - textwidget_offset
                 local y = ges.pos.y - self._frame_textwidget.dimen.y - textwidget_offset
                 self.text_widget:moveCursorToXY(x, y, true) -- restrict_to_view=true
-                self.charpos, self.top_line_num = self.text_widget:getCharPos()
+                self:resyncPos()
             end
             return true
         end
@@ -512,7 +518,7 @@ function InputText:initTextBox(text, char_added)
         }
     end
     -- Get back possibly modified charpos and virtual_line_num
-    self.charpos, self.top_line_num = self.text_widget:getCharPos()
+    self:resyncPos()
 
     self._frame_textwidget = FrameContainer:new{
         bordersize = self.bordersize,
@@ -676,22 +682,27 @@ dbg:guard(InputText, "onTextInput",
     end)
 
 function InputText:onShowKeyboard(ignore_first_hold_release)
-    Device:startTextInput()
+    if self.keyboard then
-
+        self.keyboard:showKeyboard(ignore_first_hold_release)
-    if self.is_keyboard_hidden or not self.manage_keyboard_state then
-        self.keyboard.ignore_first_hold_release = ignore_first_hold_release
-        UIManager:show(self.keyboard)
-        self.is_keyboard_hidden = false
     end
     return true
 end
 
 function InputText:onCloseKeyboard()
-    Device:stopTextInput()
+    if self.keyboard then
+        self.keyboard:hideKeyboard()
+    end
+end
 
-    if not self.is_keyboard_hidden or not self.manage_keyboard_state then
+function InputText:isKeyboardVisible()
-        UIManager:close(self.keyboard)
+    if self.keyboard then
-        self.is_keyboard_hidden = true
+        return self.keyboard:isVisible()
+    end
+end
+
+function InputText:lockKeyboard(toggle)
+    if self.keyboard then
+        return self.keyboard:lockVisibility(toggle)
     end
 end
 
@@ -873,71 +884,71 @@ end
 function InputText:leftChar()
     if self.charpos == 1 then return end
     self.text_widget:moveCursorLeft()
-    self.charpos, self.top_line_num = self.text_widget:getCharPos()
+    self:resyncPos()
 end
 
 function InputText:rightChar()
     if self.charpos > #self.charlist then return end
     self.text_widget:moveCursorRight()
-    self.charpos, self.top_line_num = self.text_widget:getCharPos()
+    self:resyncPos()
 end
 
 function InputText:goToStartOfLine()
     local new_pos = select(1, self:getStringPos({"\n", "\r"}, {"\n", "\r"}))
     self.text_widget:moveCursorToCharPos(new_pos)
-    self.charpos, self.top_line_num = self.text_widget:getCharPos()
+    self:resyncPos()
 end
 
 function InputText:goToEndOfLine()
     local new_pos = select(2, self:getStringPos({"\n", "\r"}, {"\n", "\r"})) + 1
     self.text_widget:moveCursorToCharPos(new_pos)
-    self.charpos, self.top_line_num = self.text_widget:getCharPos()
+    self:resyncPos()
 end
 
 function InputText:goToHome()
     self.text_widget:moveCursorHome()
-    self.charpos, self.top_line_num = self.text_widget:getCharPos()
+    self:resyncPos()
 end
 
 function InputText:goToEnd()
     self.text_widget:moveCursorEnd()
-    self.charpos, self.top_line_num = self.text_widget:getCharPos()
+    self:resyncPos()
 end
 
 function InputText:moveCursorToCharPos(char_pos)
     self.text_widget:moveCursorToCharPos(char_pos)
-    self.charpos, self.top_line_num = self.text_widget:getCharPos()
+    self:resyncPos()
 end
 
 function InputText:upLine()
     self.text_widget:moveCursorUp()
-    self.charpos, self.top_line_num = self.text_widget:getCharPos()
+    self:resyncPos()
 end
 
 function InputText:downLine()
     if #self.charlist == 0 then return end -- Avoid cursor moving within a hint.
     self.text_widget:moveCursorDown()
-    self.charpos, self.top_line_num = self.text_widget:getCharPos()
+    self:resyncPos()
 end
 
 function InputText:scrollDown()
     self.text_widget:scrollDown()
-    self.charpos, self.top_line_num = self.text_widget:getCharPos()
+    self:resyncPos()
 end
 
 function InputText:scrollUp()
     self.text_widget:scrollUp()
-    self.charpos, self.top_line_num = self.text_widget:getCharPos()
+    self:resyncPos()
 end
 
 function InputText:scrollToTop()
     self.text_widget:scrollToTop()
-    self.charpos, self.top_line_num = self.text_widget:getCharPos()
+    self:resyncPos()
 end
 
 function InputText:scrollToBottom()
     self.text_widget:scrollToBottom()
-    self.charpos, self.top_line_num = self.text_widget:getCharPos()
+    self:resyncPos()
 end
 
 function InputText:clear()

frontend/ui/widget/multiinputdialog.lua

@@ -218,7 +218,9 @@ end
 function MultiInputDialog:onSwitchFocus(inputbox)
     -- unfocus current inputbox
     self._input_widget:unfocus()
-    self._input_widget:onCloseKeyboard()
+    -- and close its existing keyboard (via InputDialog's thin wrapper around _input_widget's own method)
+    self:onCloseKeyboard()
+
     UIManager:setDirty(nil, function()
         return "ui", self.dialog_frame.dimen
     end)
@@ -226,7 +228,9 @@ function MultiInputDialog:onSwitchFocus(inputbox)
     -- focus new inputbox
     self._input_widget = inputbox
     self._input_widget:focus()
-    self._input_widget:onShowKeyboard()
+
+    -- Make sure we have a (new) visible keyboard
+    self:onShowKeyboard()
 end
 
 return MultiInputDialog

frontend/ui/widget/physicalkeyboard.lua

@@ -169,4 +169,11 @@ function PhysicalKeyboard:setupNumericMappingUI()
     self.dimen = keyboard_frame:getSize()
 end
 
+-- Match VirtualKeyboard's API to ease caller's life
+function PhysicalKeyboard:lockVisibility() end
+function PhysicalKeyboard:setVisibility() end
+function PhysicalKeyboard:isVisible() return true end
+function PhysicalKeyboard:showKeyboard() end
+function PhysicalKeyboard:hideKeyboard() end
+
 return PhysicalKeyboard

frontend/ui/widget/virtualkeyboard.lua

@@ -755,6 +755,8 @@ end
 
 local VirtualKeyboard = FocusManager:extend{
     name = "VirtualKeyboard",
+    visible = nil,
+    lock_visibility = false,
     covers_footer = true,
     modal = true,
     disable_double_tap = true,
@@ -929,11 +931,53 @@ end
 
 function VirtualKeyboard:onShow()
     self:_refresh(true)
+    self.visible = true
+    Device:startTextInput()
     return true
 end
 
 function VirtualKeyboard:onCloseWidget()
     self:_refresh(true)
+    self.visible = false
+    -- NOTE: This effectively stops SDL text input when a keyboard is hidden (... but navigational stuff still works).
+    --       If you instead wanted it to be enabled as long as an input dialog is displayed, regardless of VK's state,
+    --       this could be moved to InputDialog's onShow/onCloseWidget handlers (but, it would allow input on unfocused fields).
+    -- NOTE: But something more complex, possibly based on an in-class ref count would have to be implemented in order to be able to deal
+    --       with multiple InputDialogs being shown and closed in asymmetric fashion... Ugh.
+    Device:stopTextInput()
+end
+
+function VirtualKeyboard:lockVisibility(toggle)
+    self.lock_visibility = toggle
+end
+
+function VirtualKeyboard:setVisibility(toggle)
+    if self.lock_visibility then
+        return
+    end
+
+    if toggle then
+        UIManager:show(self)
+    else
+        self:onClose()
+    end
+end
+
+function VirtualKeyboard:isVisible()
+    return self.visible
+end
+
+function VirtualKeyboard:showKeyboard(ignore_first_hold_release)
+    if not self:isVisible() then
+        self.ignore_first_hold_release = ignore_first_hold_release
+        self:setVisibility(true)
+    end
+end
+
+function VirtualKeyboard:hideKeyboard()
+    if self:isVisible() then
+        self:setVisibility(false)
+    end
 end
 
 function VirtualKeyboard:initLayer(layer)

plugins/texteditor.koplugin/main.lua

@@ -545,13 +545,13 @@ function TextEditor:editFile(file_path, readonly)
         cursor_at_end = false,
         readonly = readonly,
         add_nav_bar = true,
-        keyboard_hidden = not self.show_keyboard_on_start,
+        keyboard_visible = self.show_keyboard_on_start, -- InputDialog will enforce false if readonly
         scroll_by_pan = true,
         buttons = {buttons_first_row},
-        -- Set/save view and cursor position callback
+        -- Store/retrieve view and cursor position callback
         view_pos_callback = function(top_line_num, charpos)
-            -- This same callback is called with no argument to get initial position,
+            -- This same callback is called with no arguments on init to retrieve the stored initial position,
-            -- and with arguments to give back final position when closed.
+            -- and with arguments to store the final position on close.
             if top_line_num and charpos then
                 self.last_view_pos[file_path] = {top_line_num, charpos}
             else
@@ -572,7 +572,7 @@ function TextEditor:editFile(file_path, readonly)
         end,
         -- File saving callback
         save_callback = function(content, closing) -- Will add Save/Close buttons
-            if self.readonly then
+            if readonly then
                 -- We shouldn't be called if read-only, but just in case
                 return false, _("File is read only")
             end
@@ -641,8 +641,10 @@ Do you want to keep this file as empty, or do you prefer to delete it?
 
     }
     UIManager:show(input)
+    if self.show_keyboard_on_start and not readonly then
         input:onShowKeyboard()
-    -- Note about self.readonly:
+    end
+    -- Note about readonly:
     -- We might have liked to still show keyboard even if readonly, just
     -- to use the arrow keys for line by line scrolling with cursor.
     -- But it's easier to just let InputDialog and InputText do their