git/git-gui/lib/diff.tcl

# git-gui diff viewer
# Copyright (C) 2006, 2007 Shawn Pearce

proc apply_tab_size {{firsttab {}}} {
	global repo_config ui_diff

	set w [font measure font_diff "0"]
	if {$firsttab != 0} {
		$ui_diff configure -tabs [list [expr {$firsttab * $w}] [expr {($firsttab + $repo_config(gui.tabsize)) * $w}]]
	} else {
		$ui_diff configure -tabs [expr {$repo_config(gui.tabsize) * $w}]
	}
}

proc clear_diff {} {
	global ui_diff current_diff_path current_diff_header
	global ui_index ui_workdir

	$ui_diff conf -state normal
	$ui_diff delete 0.0 end
	$ui_diff conf -state disabled

	set current_diff_path {}
	set current_diff_header {}

	$ui_index tag remove in_diff 0.0 end
	$ui_workdir tag remove in_diff 0.0 end
}

proc reshow_diff {{after {}}} {
	global file_states file_lists
	global current_diff_path current_diff_side
	global ui_diff

	set p $current_diff_path
	if {$p eq {}} {
		# No diff is being shown.
	} elseif {$current_diff_side eq {}} {
		clear_diff
	} elseif {[catch {set s $file_states($p)}]
		|| [lsearch -sorted -exact $file_lists($current_diff_side) $p] == -1} {

		if {[find_next_diff $current_diff_side $p {} {[^O]}]} {
			next_diff $after
		} else {
			clear_diff
		}
	} else {
		set save_pos [lindex [$ui_diff yview] 0]
		show_diff $p $current_diff_side {} $save_pos $after
	}
}

proc force_diff_encoding {enc} {
	global current_diff_path

	if {$current_diff_path ne {}} {
		force_path_encoding $current_diff_path $enc
		reshow_diff
	}
}

proc handle_empty_diff {} {
	global current_diff_path file_states
	global ui_diff

	set path $current_diff_path
	set s $file_states($path)
	if {[lindex $s 0] ne {_M} || [has_textconv $path]} return

	$ui_diff conf -state normal
	$ui_diff insert end [mc "* No differences detected; stage the file to de-list it from Unstaged Changes.\n"] d_info
	$ui_diff insert end [mc "* Click to find other files that may have the same state.\n"] d_rescan
	$ui_diff conf -state disabled
}

proc show_diff {path w {lno {}} {scroll_pos {}} {callback {}}} {
	global file_states file_lists
	global is_3way_diff is_conflict_diff diff_active repo_config
	global ui_diff ui_index ui_workdir
	global current_diff_path current_diff_side current_diff_header
	global current_diff_queue

	if {$diff_active || ![lock_index read]} return

	clear_diff
	if {$lno == {}} {
		set lno [lsearch -sorted -exact $file_lists($w) $path]
		if {$lno >= 0} {
			incr lno
		}
	}
	if {$lno >= 1} {
		$w tag add in_diff $lno.0 [expr {$lno + 1}].0
		$w see $lno.0
	}

	set s $file_states($path)
	set m [lindex $s 0]
	set is_conflict_diff 0
	set current_diff_path $path
	set current_diff_side $w
	set current_diff_queue {}
	ui_status [mc "Loading diff of %s..." [escape_path $path]]

	set cont_info [list $scroll_pos $callback]

	apply_tab_size 0

	if {[string first {U} $m] >= 0} {
		merge_load_stages $path [list show_unmerged_diff $cont_info]
	} elseif {$m eq {_O}} {
		show_other_diff $path $w $m $cont_info
	} else {
		start_show_diff $cont_info
	}

	global current_diff_path selected_paths
	set selected_paths($current_diff_path) 1
}

proc show_unmerged_diff {cont_info} {
	global current_diff_path current_diff_side
	global merge_stages ui_diff is_conflict_diff
	global current_diff_queue

	if {$merge_stages(2) eq {}} {
		set is_conflict_diff 1
		lappend current_diff_queue \
			[list [mc "LOCAL: deleted\nREMOTE:\n"] d= \
			    [list ":1:$current_diff_path" ":3:$current_diff_path"]]
	} elseif {$merge_stages(3) eq {}} {
		set is_conflict_diff 1
		lappend current_diff_queue \
			[list [mc "REMOTE: deleted\nLOCAL:\n"] d= \
			    [list ":1:$current_diff_path" ":2:$current_diff_path"]]
	} elseif {[lindex $merge_stages(1) 0] eq {120000}
		|| [lindex $merge_stages(2) 0] eq {120000}
		|| [lindex $merge_stages(3) 0] eq {120000}} {
		set is_conflict_diff 1
		lappend current_diff_queue \
			[list [mc "LOCAL:\n"] d= \
			    [list ":1:$current_diff_path" ":2:$current_diff_path"]]
		lappend current_diff_queue \
			[list [mc "REMOTE:\n"] d= \
			    [list ":1:$current_diff_path" ":3:$current_diff_path"]]
	} else {
		start_show_diff $cont_info
		return
	}

	advance_diff_queue $cont_info
}

proc advance_diff_queue {cont_info} {
	global current_diff_queue ui_diff

	set item [lindex $current_diff_queue 0]
	set current_diff_queue [lrange $current_diff_queue 1 end]

	$ui_diff conf -state normal
	$ui_diff insert end [lindex $item 0] [lindex $item 1]
	$ui_diff conf -state disabled

	start_show_diff $cont_info [lindex $item 2]
}

proc show_other_diff {path w m cont_info} {
	global file_states file_lists
	global is_3way_diff diff_active repo_config
	global ui_diff ui_index ui_workdir
	global current_diff_path current_diff_side current_diff_header

	# - Git won't give us the diff, there's nothing to compare to!
	#
	if {$m eq {_O}} {
		set max_sz 100000
		set type unknown
		if {[catch {
				set type [file type $path]
				switch -- $type {
				directory {
					set type submodule
					set content {}
					set sz 0
				}
				link {
					set content [file readlink $path]
					set sz [string length $content]
				}
				file {
					set fd [safe_open_file $path r]
					fconfigure $fd \
						-encoding [get_path_encoding $path]
					set content [read $fd $max_sz]
					close $fd
					set sz [file size $path]
				}
				default {
					error "'$type' not supported"
				}
				}
			} err ]} {
			set diff_active 0
			unlock_index
			ui_status [mc "Unable to display %s" [escape_path $path]]
			error_popup [strcat [mc "Error loading file:"] "\n\n$err"]
			return
		}
		$ui_diff conf -state normal
		if {$type eq {submodule}} {
			$ui_diff insert end \
				"* [mc "Git Repository (subproject)"]\n" \
				d_info
		} elseif {![catch {set type [safe_exec [list file $path]]}]} {
			set n [string length $path]
			if {[string equal -length $n $path $type]} {
				set type [string range $type $n end]
				regsub {^:?\s*} $type {} type
			}
			$ui_diff insert end "* $type\n" d_info
		}
		if {[string first "\0" $content] != -1} {
			$ui_diff insert end \
				[mc "* Binary fi