[vte/wip/egmont/bidi: 70/87] block selection copy

[Egmont Koblinger <egmontkob src gnome org>]

commit a157c99a19d47b43f0d7009f5bc15e8ac58a99a3
Author: Egmont Koblinger <egmont gmail com>
Date:   Fri Sep 28 16:57:19 2018 +0200

    block selection copy

 BIDI-STATUS           |  5 ++---
 src/vte.cc            | 44 +++++++++++++++++++++++++++++++++++---------
 src/vte/vteterminal.h |  2 +-
 3 files changed, 38 insertions(+), 13 deletions(-)
---
diff --git a/BIDI-STATUS b/BIDI-STATUS
index c6c9c387..ff78efb6 100644
--- a/BIDI-STATUS
+++ b/BIDI-STATUS
@@ -5,8 +5,8 @@ Done:
 - Possibility to make box drawing characters mirrorable (DECSET / DECRST 2500).
 - I-Beam cursor shows the character's resolved directionality when the
   paragraph has a foreign directionality character.
-- Mouse highlighting (logical in normal modes, visual in rectangle mode).
-- Copying text in logical modes.
+- Mouse highlighting, text copying (logical in normal modes, visual in
+  rectangle mode).
 - Mouse reporting.
 - Regex match and explicit hyperlink underlining on hover.
 - VTE_DEBUG=bidi highlights characters with resolved RTL directionality.
@@ -18,7 +18,6 @@ Bugs:
 - The way the modes apply to paragraphs, and what happens when a paragraph
   is split or two paragraphs are joined is just a first hack, needs to be
   reviewed, adjusted, fixed properly.
-- Copying text in rectangle mode.
 
 Missing from first release:
 - The entire screen is always invalidated. Have some more fine grained
diff --git a/src/vte.cc b/src/vte.cc
index 947b0248..41a48eb1 100644
--- a/src/vte.cc
+++ b/src/vte.cc
@@ -6202,9 +6202,6 @@ Terminal::rgb_from_index(guint index,
        }
 }
 
-// FIXMEegmont block mode doesn't work with BiDi, it won't be that easy.
-// We'll need to get the bidirow for areas not necessarily inside the current view.
-// Needs a bit of refactoring in bidi.cc.
 GString*
 Terminal::get_text(vte::grid::row_t start_row,
                              vte::grid::column_t start_col,
@@ -6218,6 +6215,9 @@ Terminal::get_text(vte::grid::row_t start_row,
        GString *string;
        struct _VteCharAttributes attr;
        vte::color::rgb fore, back;
+        vte::base::RingView *ringview = nullptr;
+        vte::base::BidiRow const *bidirow = nullptr;
+        vte::grid::column_t col_vis;
 
        if (attributes)
                g_array_set_size (attributes, 0);
@@ -6228,26 +6228,50 @@ Terminal::get_text(vte::grid::row_t start_row,
         if (start_col < 0)
                 start_col = 0;
 
-        vte::grid::column_t next_first_column = block ? start_col : 0;
-        vte::grid::column_t col = start_col;
+        if (block) {
+                /* Rectangular selection operates on the visual contents, not the logical.
+                 * m_ringview corresponds to the currently onscreen bits, therefore does not
+                 * necessarily include the entire selection.
+                 * Modifying m_ringview and then reverting would be a bit cumbersome,
+                 * creating a new one for the selection is cleaner. */
+                ringview = new vte::base::RingView();
+                ringview->set_ring(m_screen->row_data);
+                ringview->set_rows(start_row, end_row - start_row + 1);
+                ringview->set_width(m_column_count);
+                ringview->update();
+        }
+
+        vte::grid::column_t col = block ? 0 : start_col;
         vte::grid::row_t row;
-       for (row = start_row; row < end_row + 1; row++, col = next_first_column) {
+        for (row = start_row; row < end_row + 1; row++, col = 0) {
                VteRowData const* row_data = find_row_data(row);
                 gsize last_empty, last_nonempty;
                 vte::grid::column_t last_emptycol, last_nonemptycol;
-                vte::grid::column_t line_last_column = (block || row == end_row) ? end_col : G_MAXLONG;
+                vte::grid::column_t line_last_column = (!block && row == end_row) ? end_col : m_column_count;
 
                 last_empty = last_nonempty = string->len;
                 last_emptycol = last_nonemptycol = -1;
 
                attr.row = row;
-               attr.column = col;
+               attr.column = col;  // FIXME is attr.column supposed to contain logical or visual? What is it 
used for?
                pcell = NULL;
                if (row_data != NULL) {
+                        bidirow = ringview ? ringview->get_row_map(row) : nullptr;
                         while (col < line_last_column &&
                                (pcell = _vte_row_data_get (row_data, col))) {
 
-                               attr.column = col;
+                                /* In block mode, we scan each row from its very beginning to its very end 
in logical order,
+                                 * and here filter out the characters that are visually outside of the 
block. */
+                                if (bidirow) {
+                                        col_vis = bidirow->log2vis(col);
+                                        // FIXME handle CJK and friends consistently with cell_is_selected().
+                                        if (col_vis < start_col || col_vis >= end_col) {
+                                                col++;
+                                                continue;
+                                        }
+                                }
+
+                               attr.column = col;  // FIXME ditto
 
                                /* If it's not part of a multi-column character,
                                 * and passes the selection criterion, add it to
@@ -6346,6 +6370,8 @@ Terminal::get_text(vte::grid::row_t start_row,
                }
        }
 
+        delete ringview;
+
        /* Sanity check. */
         if (attributes != nullptr)
                 g_assert_cmpuint(string->len, ==, attributes->len);
diff --git a/src/vte/vteterminal.h b/src/vte/vteterminal.h
index 26ac236e..4ca6efb4 100644
--- a/src/vte/vteterminal.h
+++ b/src/vte/vteterminal.h
@@ -113,7 +113,7 @@ struct _VteTerminalClass {
 /* The structure we return as the supplemental attributes for strings. */
 struct _VteCharAttributes {
         /*< private >*/
-       long row, column;
+       long row, column;  // FIXME clarify if column is logical or visual
        PangoColor fore, back;
        guint underline:1, strikethrough:1, columns:4;
 };