50 lines
2.1 KiB
Plaintext
50 lines
2.1 KiB
Plaintext
function pan_viewport_to_contain_cursor(node)
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local safety_margin = 2*node.editor.line_height
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cursor1 = {39, 1}
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local cursor_sy = node.y + y_of_schema1(node.editor, node.editor.cursor1)/Viewport.zoom
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if Text.lt1({line=1, pos=1}, node.editor.screen_top1) then
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Viewport.y = node.y + y_of_schema1(node.editor, node.editor.screen_top1)/Viewport.zoom
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end
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if cursor_sy > Viewport.y + App.screen.height/Viewport.zoom - safety_margin then
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local cursor_y = y_of_schema1(node.editor, node.editor.cursor1)
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if Viewport.y < node.y then
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-- node starts within Viewport
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local max_cursor_y = App.screen.height - scale(node.y - Viewport.y) - safety_margin
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if cursor_y > max_cursor_y then
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-- set Viewport.y so cursor_y == max_cursor_y
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-- equation: cursor_y == App.screen.height - (node.y - Viewport.y)*Viewport.zoom - safety_margin
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-- solve for Viewport.y
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Viewport.y = node.y - (App.screen.height - cursor_y - safety_margin)/Viewport.zoom
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end
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else
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-- node extends above Viewport
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local screen_top_y = y_of_schema1(node.editor, node.editor.screen_top1)
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local min_screen_top_y = cursor_y + safety_margin - App.screen.height
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if screen_top_y < min_screen_top_y then
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screen_top_y = min_screen_top_y
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Viewport.y = node.y + screen_top_y/Viewport.zoom
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end
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end
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elseif cursor_sy < Viewport.y + safety_margin then
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local cursor_y = y_of_schema1(node.editor, node.editor.cursor1)
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if Viewport.y < node.y then
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-- node starts within Viewport
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local max_cursor_y = App.screen.height - scale(node.y - Viewport.y) - safety_margin
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if cursor_y > max_cursor_y then
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-- set Viewport.y so cursor_y == max_cursor_y
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-- equation: cursor_y == App.screen.height - (node.y - Viewport.y)*Viewport.zoom - safety_margin
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-- solve for Viewport.y
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Viewport.y = node.y - (App.screen.height - cursor_y - safety_margin)/Viewport.zoom
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end
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else
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-- node extends above Viewport
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local screen_top_y = y_of_schema1(node.editor, node.editor.screen_top1)
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local max_screen_top_y = cursor_y - safety_margin
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if screen_top_y > max_screen_top_y then
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screen_top_y = max_screen_top_y
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Viewport.y = node.y + screen_top_y/Viewport.zoom
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end
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end
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end
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end
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