663 lines
13 KiB
NASM
663 lines
13 KiB
NASM
%include "ponydos.inc"
|
||
cpu 8086
|
||
bits 16
|
||
|
||
WINDOW_STATUS_NORMAL equ 0
|
||
WINDOW_STATUS_MOVE equ 1
|
||
WINDOW_STATUS_RESIZE equ 2
|
||
|
||
; Resize button, title, space, close button
|
||
WINDOW_MIN_WIDTH equ 1 + WINDOW_TITLE_LEN + 1 + 1
|
||
WINDOW_MIN_HEIGHT equ 2
|
||
|
||
; 0x0000
|
||
jmp near process_event
|
||
|
||
; 0x0003 PROC_INITIALIZE_ENTRYPOINT
|
||
; initialize needs to preserve ds
|
||
initialize:
|
||
push ds
|
||
|
||
; On entry, ds and es will not be set correctly for us
|
||
mov bp, cs
|
||
mov ds, bp
|
||
mov es, bp
|
||
|
||
call hook_self_onto_window_chain
|
||
|
||
call render_window
|
||
|
||
; We must explicitly request redraw from the compositor
|
||
call request_redraw
|
||
|
||
pop ds
|
||
retf
|
||
|
||
; process_event needs to preserve all registers other than ax
|
||
; in:
|
||
; al = event
|
||
; bx = window ID
|
||
; cx, dx = event-specific
|
||
; out:
|
||
; ax = event-specific
|
||
process_event:
|
||
push bx
|
||
push cx
|
||
push dx
|
||
push si
|
||
push di
|
||
push bp
|
||
push ds
|
||
push es
|
||
|
||
; On entry, ds and es will not be set correctly for us
|
||
mov bp, cs
|
||
mov ds, bp
|
||
mov es, bp
|
||
|
||
cmp al, WM_PAINT
|
||
jne .not_paint
|
||
call event_paint
|
||
jmp .end
|
||
.not_paint:
|
||
|
||
cmp al, WM_MOUSE
|
||
jne .not_mouse
|
||
call event_mouse
|
||
jmp .end
|
||
.not_mouse:
|
||
|
||
cmp al, WM_KEYBOARD
|
||
jne .not_keyboard
|
||
call event_keyboard
|
||
jmp .end
|
||
.not_keyboard:
|
||
|
||
cmp al, WM_UNHOOK
|
||
jne .not_unhook
|
||
call event_unhook
|
||
jmp .end
|
||
.not_unhook:
|
||
|
||
.end:
|
||
pop es
|
||
pop ds
|
||
pop bp
|
||
pop di
|
||
pop si
|
||
pop dx
|
||
pop cx
|
||
pop bx
|
||
retf
|
||
|
||
; ------------------------------------------------------------------
|
||
; Event handlers
|
||
; ------------------------------------------------------------------
|
||
|
||
; in:
|
||
; al = WM_PAINT
|
||
; bx = window ID
|
||
; out:
|
||
; clobbers everything
|
||
event_paint:
|
||
; Forward the paint event to the next window in the chain
|
||
; We must do this before we paint ourselves, because painting must
|
||
; happen from the back to the front
|
||
; Because we only have one window, we don't need to save our own ID
|
||
mov bx, [window_next]
|
||
call send_event
|
||
|
||
mov bx, [window_width] ; Buffer width, usually same as window width
|
||
mov cx, [window_width]
|
||
mov dx, [window_height]
|
||
mov si, window_data
|
||
mov di, [window_x]
|
||
mov bp, [window_y]
|
||
|
||
cmp di, 0
|
||
jge .not_clip_left
|
||
.clip_left:
|
||
; Adjust the start of buffer to point to the first cell
|
||
; that is on screen
|
||
sub si, di
|
||
sub si, di
|
||
; Adjust window width to account for non-rendered area
|
||
; that is off screen
|
||
add cx, di
|
||
; Set X to 0
|
||
xor di, di
|
||
.not_clip_left:
|
||
|
||
mov ax, di
|
||
add ax, cx
|
||
cmp ax, COLUMNS
|
||
jle .not_clip_right
|
||
.clip_right:
|
||
; Adjust the width to only go as far as the right edge
|
||
sub ax, COLUMNS
|
||
sub cx, ax
|
||
.not_clip_right:
|
||
|
||
mov ax, bp
|
||
add ax, dx
|
||
cmp ax, ROWS
|
||
jle .not_clip_bottom
|
||
.clip_bottom:
|
||
; Adjust the height to only go as far as the bottom edge
|
||
sub ax, ROWS
|
||
sub dx, ax
|
||
.not_clip_bottom:
|
||
|
||
call PONYDOS_SEG:SYS_DRAW_RECT
|
||
|
||
ret
|
||
|
||
; in:
|
||
; al = WM_MOUSE
|
||
; bx = window ID
|
||
; cl = X
|
||
; ch = Y
|
||
; dl = mouse buttons held down
|
||
; out:
|
||
; clobbers everything
|
||
event_mouse:
|
||
test dl, MOUSE_PRIMARY | MOUSE_SECONDARY
|
||
jnz .not_end_window_change
|
||
; If we were moving or resizing the window, releasing the
|
||
; button signals the end of the action
|
||
mov byte [window_status], WINDOW_STATUS_NORMAL
|
||
.not_end_window_change:
|
||
|
||
; Expand X and Y to 16 bits for easier calculations
|
||
; Because we only have one window, we don't need to save our own ID
|
||
xor bx, bx
|
||
mov bl, ch
|
||
xor ch, ch
|
||
|
||
; Are we moving the window at the moment?
|
||
cmp byte [window_status], WINDOW_STATUS_MOVE
|
||
jne .not_moving
|
||
call move_window
|
||
.not_moving:
|
||
|
||
; Are we resizing the window at the moment?
|
||
cmp byte [window_status], WINDOW_STATUS_RESIZE
|
||
jne .not_resizing
|
||
call resize_window
|
||
.not_resizing:
|
||
|
||
; Check if the mouse is outside our window
|
||
cmp cx, [window_x]
|
||
jl .outside ; x < window_x
|
||
cmp bx, [window_y]
|
||
jl .outside ; y < window_y
|
||
mov ax, [window_x]
|
||
add ax, [window_width]
|
||
cmp ax, cx
|
||
jle .outside ; window_x + window_width <= x
|
||
mov ax, [window_y]
|
||
add ax, [window_height]
|
||
cmp ax, bx
|
||
jle .outside ; window_y + window_height <= y
|
||
|
||
.inside:
|
||
cmp byte [window_mouse_released_inside], 0
|
||
je .not_click
|
||
test dl, MOUSE_PRIMARY | MOUSE_SECONDARY
|
||
jz .not_click
|
||
.click:
|
||
call event_click
|
||
.not_click:
|
||
|
||
; We need to keep track of if the mouse has been inside our
|
||
; window without the buttons held, in order to avoid
|
||
; generating click events in cases where the cursor is
|
||
; dragged into our window while buttons are held
|
||
test dl, MOUSE_PRIMARY | MOUSE_SECONDARY
|
||
jz .buttons_not_held
|
||
.buttons_held:
|
||
mov byte [window_mouse_released_inside], 0
|
||
jmp .buttons_end
|
||
.buttons_not_held:
|
||
mov byte [window_mouse_released_inside], 1
|
||
.buttons_end:
|
||
|
||
; We must forward the event even if it was inside our
|
||
; window, to make sure other windows know when the mouse
|
||
; leaves them
|
||
; Set x and y to 255 so that windows below ours don't think
|
||
; the cursor is inside them
|
||
; Also clear the mouse buttons – not absolutely necessary
|
||
; but it's cleaner if other windows don't get any
|
||
; information about the mouse
|
||
mov al, WM_MOUSE
|
||
mov bx, [window_next]
|
||
mov cx, 0xffff
|
||
xor dl, dl
|
||
call send_event
|
||
ret
|
||
|
||
.outside:
|
||
mov byte [window_mouse_released_inside], 0
|
||
|
||
; Not our window, forward the event
|
||
mov al, WM_MOUSE
|
||
mov ch, bl ; Pack the X and Y back into cx
|
||
mov bx, [window_next]
|
||
call send_event
|
||
ret
|
||
ret
|
||
|
||
; in:
|
||
; bx = Y
|
||
; cx = X
|
||
; dl = mouse buttons
|
||
event_click:
|
||
; This is not a true event passed into our event handler, but
|
||
; rather one we've synthetized from the mouse event
|
||
; The reason we synthetize this event is because most interface
|
||
; elements react to clicks specifically, so having this event
|
||
; making implementing them easier
|
||
|
||
; Raising a window is done by first unhooking, then rehooking it to
|
||
; the window chain
|
||
call unhook_self_from_window_chain
|
||
call hook_self_onto_window_chain
|
||
call request_redraw
|
||
|
||
; Did the user click the title bar?
|
||
cmp [window_y], bx
|
||
jne .not_title_bar
|
||
.title_bar:
|
||
; Did the user click the window close button?
|
||
mov ax, [window_x]
|
||
add ax, [window_width]
|
||
dec ax
|
||
cmp ax, cx
|
||
jne .not_close
|
||
.close:
|
||
call unhook_self_from_window_chain
|
||
; Nothing can call into us again after we unhook
|
||
; the window, so deallocate the memory we have
|
||
; reserved
|
||
call deallocate_own_memory
|
||
; We don't need to call request_redraw here, since
|
||
; it will be called unconditionally above
|
||
jmp .title_bar_end
|
||
.not_close:
|
||
|
||
; Did the user click on the resize button?
|
||
cmp [window_x], cx
|
||
jne .not_resize
|
||
.resize:
|
||
mov byte [window_status], WINDOW_STATUS_RESIZE
|
||
jmp .title_bar_end
|
||
.not_resize:
|
||
|
||
; Clicking on the title bar signals beginning of a window
|
||
; move
|
||
mov byte [window_status], WINDOW_STATUS_MOVE
|
||
mov ax, [window_x]
|
||
sub ax, cx
|
||
mov [window_move_x_offset], ax
|
||
.title_bar_end:
|
||
.not_title_bar:
|
||
|
||
.end:
|
||
ret
|
||
|
||
; in:
|
||
; al = WM_KEYBOARD
|
||
; bx = window ID
|
||
; cl = typed character
|
||
; ch = pressed key
|
||
; out:
|
||
; clobbers everything
|
||
event_keyboard:
|
||
; Unlike other events, keyboard events are not forwarded
|
||
; Since we do not care about the keyboard for this app, we just
|
||
; swallow the event
|
||
ret
|
||
|
||
; in:
|
||
; al = WM_UNHOOK
|
||
; bx = window ID
|
||
; cx = window ID of the window to unhook from the window chain
|
||
; out:
|
||
; ax = own window ID if we did not unhook
|
||
; next window ID if we did
|
||
; clobbers everything else
|
||
event_unhook:
|
||
cmp bx, cx
|
||
je .unhook_self
|
||
|
||
; Save our own ID
|
||
push bx
|
||
|
||
; Propagate the event
|
||
mov bx, [window_next]
|
||
call send_event
|
||
|
||
; Update window_next in case the next one unhooked
|
||
mov [window_next], ax
|
||
|
||
; Return our own ID
|
||
pop ax
|
||
ret
|
||
|
||
.unhook_self:
|
||
; Return window_next to the caller, unhooking us from the
|
||
; chain
|
||
mov ax, [window_next]
|
||
ret
|
||
|
||
; ------------------------------------------------------------------
|
||
; Event handler subroutines
|
||
; ------------------------------------------------------------------
|
||
|
||
; in:
|
||
; bx = Y
|
||
; cx = X
|
||
move_window:
|
||
push ax
|
||
|
||
; Offset the X coördinate so that the apparent drag position
|
||
; remains the same
|
||
mov ax, cx
|
||
add ax, [window_move_x_offset]
|
||
|
||
; Only do an update if something has changed. Reduces flicker
|
||
cmp [window_x], ax
|
||
jne .update_location
|
||
cmp [window_y], bx
|
||
jne .update_location
|
||
jmp .end
|
||
|
||
.update_location:
|
||
mov [window_x], ax
|
||
mov [window_y], bx
|
||
call request_redraw
|
||
|
||
.end:
|
||
pop ax
|
||
ret
|
||
|
||
; in:
|
||
; bx = Y
|
||
; cx = X
|
||
resize_window:
|
||
push ax
|
||
push bx
|
||
push bp
|
||
|
||
; Calculate new width
|
||
mov ax, [window_width]
|
||
add ax, [window_x]
|
||
sub ax, cx
|
||
|
||
cmp ax, WINDOW_MIN_WIDTH
|
||
jge .width_large_enough
|
||
mov ax, WINDOW_MIN_WIDTH
|
||
.width_large_enough:
|
||
|
||
cmp ax, COLUMNS
|
||
jle .width_small_enough
|
||
mov ax, COLUMNS
|
||
.width_small_enough:
|
||
|
||
; Calculate new height
|
||
mov bp, [window_height]
|
||
add bp, [window_y]
|
||
sub bp, bx
|
||
|
||
cmp bp, WINDOW_MIN_HEIGHT
|
||
jge .height_large_enough
|
||
mov bp, WINDOW_MIN_HEIGHT
|
||
.height_large_enough:
|
||
|
||
cmp bp, ROWS
|
||
jle .height_small_engough
|
||
mov bp, ROWS
|
||
.height_small_engough:
|
||
|
||
; Only do an update if something has changed. Reduces flicker
|
||
cmp [window_width], ax
|
||
jne .update_size
|
||
cmp [window_height], bp
|
||
jne .update_size
|
||
jmp .end
|
||
|
||
.update_size:
|
||
mov bx, [window_x]
|
||
add bx, [window_width]
|
||
sub bx, ax
|
||
mov [window_x], bx
|
||
mov [window_width], ax
|
||
|
||
mov bx, [window_y]
|
||
add bx, [window_height]
|
||
sub bx, bp
|
||
mov [window_y], bx
|
||
mov [window_height], bp
|
||
|
||
call render_window
|
||
|
||
call request_redraw
|
||
|
||
.end:
|
||
pop bp
|
||
pop bx
|
||
pop ax
|
||
|
||
render_window:
|
||
push ax
|
||
push cx
|
||
push dx
|
||
push si
|
||
push di
|
||
|
||
; Clear window to be black-on-white
|
||
mov di, window_data
|
||
mov ax, [window_width]
|
||
mov cx, [window_height]
|
||
mul cx
|
||
mov cx, ax
|
||
mov ax, 0xf000 ; Attribute is in the high byte
|
||
rep stosw
|
||
|
||
; Set title bar to be white-on-black
|
||
mov di, window_data
|
||
mov ax, 0x0f00
|
||
mov cx, [window_width]
|
||
rep stosw
|
||
|
||
; Add title bar buttons
|
||
mov di, window_data
|
||
mov byte [di], 0x17 ; Resize arrow
|
||
add di, [window_width]
|
||
add di, [window_width]
|
||
sub di, 2
|
||
mov byte [di], 'x' ; Close button
|
||
|
||
; Add window title
|
||
mov di, window_data
|
||
add di, 2
|
||
mov si, window_title
|
||
mov cx, WINDOW_TITLE_LEN
|
||
.copy_title:
|
||
lodsb
|
||
stosb
|
||
inc di
|
||
loop .copy_title
|
||
|
||
; Add message
|
||
; This may overflow the available visual space, but since we always
|
||
; allocate the maximum size for the window, this is not a buffer
|
||
; overflow
|
||
mov di, window_data
|
||
add di, [window_width]
|
||
add di, [window_width]
|
||
mov si, message
|
||
mov cx, MESSAGE_LEN
|
||
.copy_message:
|
||
lodsb
|
||
stosb
|
||
inc di
|
||
loop .copy_message
|
||
|
||
pop di
|
||
pop si
|
||
pop dx
|
||
pop cx
|
||
pop ax
|
||
ret
|
||
|
||
; ------------------------------------------------------------------
|
||
; Window chain
|
||
; ------------------------------------------------------------------
|
||
|
||
; in:
|
||
; al = event
|
||
; bx = window to send the event to
|
||
; cx, dx = event-specific
|
||
; out:
|
||
; ax = event-specific, 0 if bx=0
|
||
send_event:
|
||
test bx, bx
|
||
jnz .non_zero_id
|
||
|
||
; Returning 0 if the window ID is 0 makes window unhooking simpler
|
||
xor ax, ax
|
||
ret
|
||
|
||
.non_zero_id:
|
||
push bp
|
||
|
||
; Push the return address
|
||
push cs
|
||
mov bp, .end
|
||
push bp
|
||
|
||
; Push the address we're doing a far-call to
|
||
mov bp, bx
|
||
and bp, 0xf000 ; Highest nybble of window ID marks the segment
|
||
push bp
|
||
xor bp, bp ; Event handler is always at address 0
|
||
push bp
|
||
|
||
retf
|
||
|
||
.end:
|
||
pop bp
|
||
ret
|
||
|
||
hook_self_onto_window_chain:
|
||
push ax
|
||
push es
|
||
|
||
mov ax, PONYDOS_SEG
|
||
mov es, ax
|
||
|
||
; Window ID is made of the segment (top nybble) and an arbitrary
|
||
; process-specific part (lower three nybbles). Since we only have
|
||
; one window, we can leave the process-specific part as zero
|
||
mov ax, cs
|
||
|
||
xchg [es:GLOBAL_WINDOW_CHAIN_HEAD], ax
|
||
|
||
; Save the old head of the chain, so that we can propagate events
|
||
; down to it
|
||
mov [window_next], ax
|
||
|
||
pop es
|
||
pop ax
|
||
ret
|
||
|
||
unhook_self_from_window_chain:
|
||
push bx
|
||
push cx
|
||
push es
|
||
|
||
mov ax, PONYDOS_SEG
|
||
mov es, ax
|
||
|
||
mov al, WM_UNHOOK
|
||
mov bx, [es:GLOBAL_WINDOW_CHAIN_HEAD]
|
||
; Our window ID is just our segment, see the comment in
|
||
; hook_self_onto_window_chain
|
||
mov cx, cs
|
||
call send_event
|
||
|
||
; Update the head of the chain, in case we were at the head
|
||
mov [es:GLOBAL_WINDOW_CHAIN_HEAD], ax
|
||
|
||
pop es
|
||
pop cx
|
||
pop bx
|
||
ret
|
||
|
||
; ------------------------------------------------------------------
|
||
; Memory management
|
||
; ------------------------------------------------------------------
|
||
|
||
deallocate_own_memory:
|
||
push bx
|
||
push cx
|
||
push es
|
||
|
||
mov bx, PONYDOS_SEG
|
||
mov es, bx
|
||
|
||
; Segment 0xn000 corresponds to slot n in the allocation table
|
||
mov bx, cs
|
||
mov cl, 12
|
||
shr bx, cl
|
||
|
||
mov byte [es:GLOBAL_MEMORY_ALLOCATION_MAP + bx], 0
|
||
|
||
pop es
|
||
pop cx
|
||
pop bx
|
||
ret
|
||
|
||
; ------------------------------------------------------------------
|
||
; Painting
|
||
; ------------------------------------------------------------------
|
||
|
||
request_redraw:
|
||
push ax
|
||
push es
|
||
|
||
mov ax, PONYDOS_SEG
|
||
mov es, ax
|
||
|
||
mov byte [es:GLOBAL_REDRAW], 1
|
||
|
||
pop es
|
||
pop ax
|
||
ret
|
||
|
||
; ------------------------------------------------------------------
|
||
; Variables
|
||
; ------------------------------------------------------------------
|
||
|
||
window_title db 'Hello'
|
||
.end:
|
||
WINDOW_TITLE_LEN equ window_title.end - window_title
|
||
|
||
message db 'Hello, world!'
|
||
.end:
|
||
MESSAGE_LEN equ message.end - message
|
||
|
||
window_next dw 0xffff
|
||
window_x dw 9
|
||
window_y dw 19
|
||
window_width dw MESSAGE_LEN
|
||
window_height dw 2
|
||
|
||
window_mouse_released_inside db 0
|
||
window_status db WINDOW_STATUS_NORMAL
|
||
window_move_x_offset dw 0
|
||
|
||
section .bss
|
||
window_data resw 25*80
|