Refactorize check button pressed (#340)

engine/events/cinnabar_lab.asm

@@ -27,7 +27,7 @@ GiveFossilToCinnabarLab::
 	ld hl, wd730
 	res 6, [hl]
 	call HandleMenuInput
-	bit 1, a ; pressed B?
+	bit BIT_B_BUTTON, a
 	jr nz, .cancelledGivingFossil
 	ld hl, wFilteredBagItems
 	ld a, [wCurrentMenuItem]

engine/events/hidden_objects/bills_house_pc.asm

@@ -95,7 +95,7 @@ BillsHousePokemonList::
 	call PrintText
 	call SaveScreenTilesToBuffer2
 	call HandleMenuInput
-	bit 1, a ; pressed b
+	bit BIT_B_BUTTON, a
 	jr nz, .cancel
 	ld a, [wCurrentMenuItem]
 	add EEVEE

engine/events/hidden_objects/school_blackboard.asm

@@ -36,7 +36,7 @@ LinkCableHelp::
 	ld hl, LinkCableHelpText2
 	call PrintText
 	call HandleMenuInput
-	bit 1, a ; pressed b
+	bit BIT_B_BUTTON, a
 	jr nz, .exit
 	ld a, [wCurrentMenuItem]
 	cp 3 ; pressed a on "STOP READING"
@@ -122,9 +122,9 @@ ViridianSchoolBlackboard::
 	ld hl, ViridianSchoolBlackboardText2
 	call PrintText
 	call HandleMenuInput ; pressing up and down is handled in here
-	bit 1, a ; pressed b
+	bit BIT_B_BUTTON, a ; pressed b
 	jr nz, .exitBlackboard
-	bit 4, a ; pressed right
+	bit BIT_D_RIGHT, a
 	jr z, .didNotPressRight
 	; move cursor to right column
 	ld a, 2
@@ -137,7 +137,7 @@ ViridianSchoolBlackboard::
 	ld [wMenuItemOffset], a
 	jr .blackboardLoop
 .didNotPressRight
-	bit 5, a ; pressed left
+	bit BIT_D_LEFT, a
 	jr z, .didNotPressLeftOrRight
 	; move cursor to left column
 	ld a, 2

engine/events/prize_menu.asm

@@ -31,7 +31,7 @@ CeladonPrizeMenu::
 	ld hl, WhichPrizeTextPtr
 	call PrintText
 	call HandleMenuInput ; menu choice handler
-	bit 1, a ; keypress = B (Cancel)
+	bit BIT_B_BUTTON, a
 	jr nz, .noChoice
 	ld a, [wCurrentMenuItem]
 	cp 3 ; "NO,THANKS" choice

engine/events/vending_machine.asm

@@ -31,7 +31,7 @@ VendingMachineMenu::
 	ld hl, wd730
 	res 6, [hl]
 	call HandleMenuInput
-	bit 1, a ; pressed B?
+	bit BIT_B_BUTTON, a
 	jr nz, .notThirsty
 	ld a, [wCurrentMenuItem]
 	cp 3 ; chose Cancel?